Download Hi-Res ImageDownload to MS-PowerPointCite This:Environ. Sci. Technol. 2024, 58, 17, 7457-7468
Your access to this publication has been provided by Learn More
Bioremediation and Biotechnology
Biological Self-Assembled Transmembrane Electron Conduits for High-Efficiency Ammonia Production in Microbial ElectrosynthesisClick to copy article linkArticle link copied!
- Yao LiYao LiKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian116024, P.R. ChinaMore by Yao Li
- Sen Qiao*Sen Qiao*Email: qscyj@mail.dlut.edu.cnKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian116024, P.R. ChinaMore by Sen Qiao
- Meiwei GuoMeiwei GuoKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian116024, P.R. ChinaMore by Meiwei Guo
- Liying ZhangLiying ZhangKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian116024, P.R. ChinaMore by Liying Zhang
- Guangfei LiuGuangfei LiuKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian116024, P.R. ChinaMore by Guangfei Liu
- Jiti ZhouJiti ZhouKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian116024, P.R. ChinaMore by Jiti Zhou
Abstract
Click to copy section linkSection link copied!
Usually, CymA is irreplaceable as the electron transport hub in Shewanella oneidensis MR-1 bidirectional electron transfer. In this work, biologically self-assembled FeS nanoparticles construct an artificial electron transfer route and implement electron transfer from extracellular into periplasmic space without CymA involvement, which present similar properties to type IV pili. Bacteria are wired up into a network, and more electron transfer conduits are activated by self-assembled transmembrane FeS nanoparticles (electron conduits), thereby substantially enhancing the ammonia production. In this study, we achieved an average NH4+-N production rate of 391.8 μg·h–1·L reactor–1 with the selectivity of 98.0% and cathode efficiency of 65.4%. Additionally, the amide group in the protein-like substances located in the outer membrane was first found to be able to transfer electrons from extracellular into intracellular with c-type cytochromes. Our work provides a new viewpoint that contributes to a better understanding of the interconnections between semiconductor materials and bacteria and inspires the exploration of new electron transfer chain components.
This publication is licensed under the terms of your institutional subscription. Request reuse permissions.
Copyright © 2024 American Chemical Society
Synopsis
This study broke the conventional view that CymA protein was irreplaceable in extracellular electron transfer in Shewanella oneidensis MR-1.
Introduction
Click to copy section linkSection link copied!
Ammonia (NH3) is an essential raw material for industry and agriculture. (1) According to the International Energy Agency (IEA), ammonia production is around 200 million tons per year and 85% of them is consumed as a feedstock for nitrogen fertilizer. (2) Lately, NH3 is also considered as an alternative fuel and energy storage carrier due to superior gravimetric hydrogen density (17.8 wt %) and sizable volumetric energy density (15.6 MJ L–1). (3) The traditional ammonia industry (Haber–Bosch process) requires an internal temperature over 800 °F and a pressure of about 200 atm, which demands enormous energy (approximately 1.8% of the world’s energy consumption) and resulted in 235 million tons of CO2 emissions annually (about 1.4% of global CO2 emissions). (4,5)
Electrosynthesis of ammonia is an alternative way forward for NH3 production via reducing nitrate (NO3–), which has a more substantial solubility (92 g/100 g water) and a lower N═O rupture energy (204 kJ mol–1) compared to N2. (6,7) Furthermore, NO3– pollution harms human health and environmental sustainability by producing carcinogenic nitrosamines, causing methemoglobinemia and eutrophication. (8) Electricity-driven NO3–-to-NH3 conversion is an attractive approach in terms of saving fossil fuels, yet still limited by low product selectivity in neutral and acidic environment. (9)
The emerging microbial electrosynthesis (MES) systems, which integrate the merits of electronic materials with biocatalysts (electrotrophs), offer innovative opportunities by overcoming the limitations of chemical catalysts. Biocatalysts have the exclusive advantage of high selectivity and mild reaction conditions, as well as being reproducible. (10) Recently, our group injected electrons from cathodes directly into Shewanella oneidensis MR-1 wild-type strain (S. oneidensis) by reversing the typical extracellular electron transfer (EET) chain, developing the cathode-dependent dissimilatory nitrate to ammonia (DNRA) process. (11) Unlike conventional chemical catalysts in which multiple intermediates (such as NO2–, NO, and NH2OH) are present in the multielectron transfer process, the DNRA process stepwise reduces nitrate to nitrite and nitrite to ammonium. (12) However, the EET chain is unwired due to the inherited 3D cell structure, thus limiting the performance. (13) Given that the Fe–S cluster tends to act as a cofactor for electron transfer proteins, it is a scientific gap whether electrons could be transferred to terminal enzymes in the periplasmic space via biosynthesized FeS without CymA involvement (indispensable inner membrane protein in outward EET). (14) If as our expectation, electron transfer rate and cathode efficiency could be expedited, we could further implement highly efficient MES.
Herein, we report a strategy of biosynthesized FeS nanoparticles (NPs) as wired electron transfer conduits at the interface between the cell and the cathode, designing S. oneidensis@FeS hybrid systems to address the limitation of transmembrane electron transport for improving the NH3 production performance. The well-designed hybrid system demonstrated the dramatically enhanced electron uptake efficiency and allowed inward EET no longer relying on CymA solely. As a proof of concept, the biohybrid system achieved an average NH4+-N production rate of 391.8 μg·h–1·L reactor–1 with the average selectivity of 98.0% and an average cathode efficiency of 65.4%. The study offers an interesting perspective into the interconnections between semiconductor materials and bacteria, inspires the exploration of new electron transfer chain components, and opens an avenue for achieving environmentally friendly and high-efficiency conversion of NO3– to NH3 with ultrahigh product selectivity.
Materials and Methods
Click to copy section linkSection link copied!
Biosynthesis of FeS Nanoparticles
An overnight suspension of S. oneidensis was inoculated into Luria–Bertani broth at a ratio of 1:100 and incubated at 30 ± 1.0 °C for approximately 12 h to reach the end of the logarithmic growth phase. Residues were rinsed using a 0.01 M phosphate buffer solution (PBS). FeS biosynthesis experiments were performed in 100 mL bottles containing M9 salt medium supplemented with 0.50 g/L yeast extract, 0.25 g/L peptone, 18 mM sodium lactate, 2 mM Fe(III)-citrate, and different concentrations of Na2S2O3 (0, 0.5, 1, 2, 4, and 8 mM) for 24 h. To maintain anaerobic conditions, each bottle was purged with nitrogen for 20 min and subsequently sealed with butyl rubber stoppers and aluminum caps. S. oneidensis was introduced into the bottle with an initial optical density (OD600) of 0.5. The bottles were incubated at 30 ± 1.0 °C on a shaker table (180 rpm). During the incubation, samples were collected periodically to monitor the Fe(II) concentration. Before the experiment, all glassware was sterilized in an autoclave (LDZX-30KBS, Shenan, China) at 121 °C for 20 min. The sample collection and pretreatment steps were carried out within an anaerobic glovebox (YQX-II, CIMO, China). Depending on the electrochemical analysis results, we chose the most suitable biosynthesis conditions for subsequent experiments. Details are shown in Figures S1–S3.
Preparation of Artificial Biofilms
Following biosynthesis, the bacteria were centrifuged with 0.1 M PBS at 10,000 rpm for 5 min and washed thrice. Then, they were subsequently adjusted to the same level (0.5 mg of protein) with 4 mL of PBS. A 200 μL Nafion membrane solution as an immobilization agent was added to the bacterial solution to encapsulate S. oneidensis. Artificial biofilms were created by uniformly dropping all the bacterial solution onto carbon felts (60 × 60 × 2 mm) and then air-dried under 30 ± 1.0 °C for 6 h. (15) The entire procedure was carried out under aseptic and anaerobic conditions.
Microbial Electrosynthesis System Setup and Operation
Artificial biofilms were employed as cathodes in a MES system with a potentiostat (DJS-292, Leici, China), applying a constant voltage of −0.41 V vs SHE. After gently sparging with helium gas for 20 min to remove dissolved oxygen, three parallel MES reactors were sealed and operated at 30 ± 1.0 °C in a shaker table (150 rpm). Figure S4 illustrates the use of carbon felts as electrode materials. The counter electrode (anode) was measured as 60 × 80 × 2 mm, while the working electrode (biocathode) had dimensions of 60 × 60 × 2 mm. To pretreat the carbon felt, a sequential treatment was conducted using 1 M sulfuric acid, ultrapure water, and 1 M acetone to remove surface-deposited inorganic particles, metal ions, and organic residues. This was followed by heating at 450 °C for 30 min in a muffle furnace (TM-0914, Meicheng, China) to enhance thermal stability and eliminate impurities. (16) The practical operational volume of the dual-chamber reactor was 200 mL, and the distance between the cathode and the anode was 12 cm. The two chambers were divided by a proton exchange membrane (Nafion 117, Dupont, USA), which was consecutively pretreated with 5% hydrogen peroxide, ultrapure water, and 5% sulfuric acid at 80 °C for 1 h. (17) Prior to the experiments, all glassware and metal components were subjected to sterilization. The Ag/AgCl electrode (+197 mV vs SHE) was immersed in 70% alcohol for 6 h and sterilized on a clean bench under UV irradiation (ZHJH-1115B, Zhicheng, China). The composition of the electrolyte solution is shown in Table S1. In each cycle, S. oneidensis and S. oneidensis@FeS systems were operated for 5 and 3 days to allow as much nitrate reduction as possible. At the end of each cycle, a sterilized 0.1 M PBS solution was employed to wash the anode and cathode chambers thrice. Afterward, the sterile electrolyte solution was readded for the next cycle. The complete MES experiment was run for three cycles, respectively.
Characteristics of the Biosynthesis-FeS and Biohybrid
The morphologies of the S. oneidensis and S. oneidensis@FeS systems were examined by a scanning electron microscope (SEM, SU5000, Hitachi, Japan). The samples were centrifuged with 0.1 M PBS at 10,000 rpm for 5 min and washed three times and then fixed with 2.5% (v/v) glutaraldehyde solution at 4 °C for 12 h. After that, they were gradient dehydrated by centrifugation at 10,000 rpm for 5 min in various ethanol concentrations (0, 20, 40, 60, 80, 90, 95, 100% (v/v)) and dispersed in ultrapure water, and then 20 μL was taken on a silicon wafer (3 × 3 mm), leaving the samples to dry and spraying platinum for SEM observation. Elemental analysis was conducted utilizing energy-dispersive X-ray spectroscopy. The size distribution of biosynthesis-FeS was analyzed by image analysis software (Nano Measurer), with a minimum of 100 NPs measured in each image for statistical analysis. Ultrathin cell slices were mounted on copper grids for high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) image capture and elemental analysis (HT7700, Hitachi, Japan) at an acceleration voltage of 200 kV. Before observation, samples were washed by centrifugation, fixed and gradient dehydrated (as described previously), and then stained with osmic acid and impregnated with epoxy resin. Subsequently, the samples were sliced by ultramicrotome. The biohybrids at different precursor concentrations were characterized by ultraviolet–visible near-infrared spectroscopy (UV–vis-NIR, SolidSpec-3700, Shimadzu, Japan). For crystal structure, the vacuum freeze-dried powder of samples was subjected to X-ray powder diffraction spectroscopy (XRD, D8 Advance, Bruker, Germany). The valence states were determined through X-ray photoelectron spectroscopy (XPS, ESCALAB XI+, Thermo, UK).
Electrochemical Measurement and Analysis
A data acquisition card (DAQM-4212, Zhouzheng, China) measured the current in the dual-chamber reactors. The current density (J, A/m2), total accumulated electrons (C, A·S), cathode efficiency (ηE, %), and selectivity (%) were calculated according to the following equations:where I (A) shows the cathode current; S (m2) indicates the cathode area; T (s) is the reaction time per cycle; F denotes the Faradaic constant (96485.3 C/mols); V (L) represents the reaction volume; n1 and n2 (mols/mol) express the numbers of electrons per mole of nitrate reduced to ammonia and nitrite, respectively; ΔNH4+-N, ΔNO2–-N, and ΔNO3–-N (mg/L) are the concentration variations of N in ammonia, nitrite, and nitrate, separately; and M (g/mol) refers to the relative atomic mass of nitrogen.
(1)
(2)
(3)
(4)
The electrochemical property of the biocathode was analyzed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) with an electrochemical workstation (CHI660E, Chenhua, China). CV was performed in 0.1 M PBS from −0.8 to 0.6 V vs Ag/AgCl at a scan rate of 50 mv/s, and EIS was carried out over a frequency range of 100 kHz to 0.01 Hz with a sinusoidal perturbation amplitude of 5 mV. Equivalent circuit and resistance values were defined by ZView software. For biohybrids with different precursor concentrations, 10 mL of the bacteria solution after 24 h biosynthesis was taken as well as centrifuged and washed three times with 0.1 M PBS at 10,000 rpm for 5 min. Afterward, they were dispersed in 1 mL of PBS containing 50 μL of Nafion solution. Finally, 100 μL was taken from it and coated on the surface of pretreated carbon felt (10 × 10 × 2 mm) as the working electrode. The cathodic biofilm, platinum sheet electrode (1.5 × 1.5 cm), and Ag/AgCl electrode were the working, counter, and reference electrodes, respectively. Before electrochemical measurement, the electrolyte was aerated with N2 for 20 min to remove dissolved oxygen and the unit was set to open circuit for 2 h.
Biofilm Spatial Morphology Test
The state of the cathode biofilm was visualized with confocal laser scanning microscopy (CLSM, FV1200, Olympus, Japan). In order to dye the biofilm, a LIVE/DEAD BacLight Bacterial Viability Kit was applied. The biofilm samples were gently rinsed twice with sterile saline, and 0.5 mL of staining solution (2 mL of sterile saline with 2 μL of SYTO-9 and 4 μL of PI) were added dropwise to the sample surface and incubated for 15 min at 37 °C protected from light. The staining solution was washed with sterile saline after staining. Details are shown in Figures S5 and S6.
Molecular-Level Tests for Surface Group
Artificial biofilms were employed as the working electrode for the electrochemical in-situ Fourier transform infrared spectroscopy test. An electrochemical workstation (CHI660E, Chenhua, China) provided the working potential with a gradient ranging from −0.9 to 0.4 V vs Ag/AgCl. A Fourier transform infrared spectroscopy spectrometer (VERTEX 70, Bruker, Germany) was applied. Additionally, a Ag/AgCl electrode and a Pt sheet were used as the reference and counter electrodes, respectively. All electrodes were placed into the IR cell to form a single-chamber reactor, and 0.1 M D2O was utilized as the electrolyte to mitigate any spectral dose effects.
Other Analysis
The concentrations of NO3–-N, NO2–-N, and NH4+-N were determined by a spectrophotometer (SPECORD 50 PLUS, Analytik Jena AG, Germany) with the salicylic acid method, ethylenediamine dihydrochloride colorimetric method, and sodium hypochlorite–salicylic acid method, respectively. (18,19) The Fe(II) concentration was measured via o-phenanthroline spectrophotometry. (20) The total nitrogen concentration in the electrolyte was calculated as the sum of the nitrate, nitrite, and ammonia. In order to measure the total organic carbon (TOC), a TOC and total nitrogen analyzer (multi N/C 2100S, Analytik Jena AG, Germany) was employed. The Bradford Protein Assay Kit (C503031, Sangon Biotech (Shanghai) Co., Ltd.) was utilized to quantify the protein content.
Results and Discussion
Click to copy section linkSection link copied!
Characteristics of the Biosynthesis-FeS
The microstructure, crystalline phase composition, and elemental valence states of the S. oneidensis@FeS system were analyzed by SEM, HAADF-STEM, XRD, and XPS, respectively. In the biohybrid system, the spherical NPs were uniformly anchored on the bacterial surface and wrapped tightly around the bacterial cell compared to the control group (Figure 1A,B). Elemental mapping revealed sulfur and iron as the main elements in the NPs (Figure S7), with a mean particle size of 37.1 ± 8.2 nm (Figure 1C). In this dimensional range, the biohybrid systems were reported to have the most extraordinary electron transfer efficiency. (21) According to the HAADF-STEM images after the cell slice, FeS NPs emerged as bright white dots, and they accessed into the intracellular environment (Figure 1D–G). This spatial morphology allowed FeS NPs to bridge the intracellular and extracellular environments, probably dramatically facilitating the electron transfer. (001), (101), and (200) facets as typical peaks indicated that the NPs were mackinawite FeS (Figure 1H). Therein, poor crystallinity was associated with insufficient low ambient pH and solid growth duration. (22) Three types of chemical bonds occurred in the fitted curves with the Fe2p3/2 spectra: Fe(II)–S (707.2 eV), Fe(II)–O (709.7 eV), and Fe(III)–S (711.3 eV) (Figure 1I). Moreover, in the S2p spectra, the peaks are attributed to S2– (160.9 eV) and S22– (162.1 eV) (Figure 1J). The absence of other sulfur-containing substances (e.g., SO32–, S0, and Sn2–) indicated a high-selectivity biosynthesis of FeS NPs. (23)
Figure 1
Figure 1. Characteristics of the S. oneidensis@FeS system.
SEM images of (A) S. oneidensis and (B) S. oneidensis@FeS (scale bars: 100 nm). (C) The FeS NP size distribution. (D) HAADF-STEM image of the sliced S. oneidensis@FeS (scale bars: 200 nm) and (E–G) EDS mapping of the sliced S. oneidensis@FeS (scale bars: 200 nm). (H) XRD spectra of S. oneidensis@FeS. (I, J) XPS spectra of the S. oneidensis@FeS.
Ammonium Production Performance
The MES systems were operated under a constant potential of −0.41 V vs SHE in order to prevent hydrogen evolution (Figure S4). (24) This low applied voltage aimed to avoid the interference of hydrogen as an electron donor for S. oneidensis and to maximize cathodic electron uptake for nitrate reduction. (25) NO3– removal performance is shown in Figure 2A,B by S. oneidensis and S. oneidensis@FeS systems with the identical initial NO3–-N concentration of approximately 20.0 mg/L. During the reaction, TOC concentrations in both systems were stabilized around 1.0 mg/L without obvious fluctuations, excluding the contribution of organic carbons (Figure S8). Moreover, the nitrate reduction occurred stepwise to nitrite and then nitrite to ammonium, with the cathode as the sole electron donor, and the total nitrogen amount was maintained in equilibrium, consistent with previous studies. (11,12,26) Compared to S. oneidensis, S. oneidensis@FeS system completely reduced NO3– to NH4+ within 72 h without NO2– accumulation, whereas the former still exhibited an average of 3.1 mg/L NO2–-N left in the 120 h reaction period. In addition, the S. oneidensis@FeS system achieved a superior selectivity (the maximum of 99.1%) and NH4+-N production rate (the maximum of 395.0 μg·h–1·L reactor–1) in three cycles (Figure 2C,D). For S. oneidensis, the selectivity and NH4+-N production rates reached maximum values of 93.7% and 212.0 μg·h–1·L reactor–1, respectively; these were significantly lower than those of the S. oneidensis@FeS system.
Figure 2
Figure 2. Nitrate reduction performances in S. oneidensis and S. oneidensis@FeS systems.
NO3–-N, NO2–-N, and NH4+-N concentrations in the (A) S. oneidensis and (B) S. oneidensis@FeS system. Yield evaluation of the DNRA process in (C) S. oneidensis and (D) S. oneidensis@FeS system. Each experiment was performed in triplicate, and error bars indicate the standard deviation.
In order to further clarify the role of FeS NPs in reversed EET, mutant strains (ΔomcA/mrtC and ΔcymA) were utilized for measurement, since both omcA/mtrC and cymA were critical proteins in EET of S. oneidensis. (27) Figure S9 illustrates FeS NPs (black solids) could be biosynthesized by both S. oneidensis MR-1 mutants. In mutant strains, NPs were embedded in the outer membrane and aligned in the periplasmic space (Figure S10). In contrast to the wild-type strain (referring to S. oneidensis in the above paragraph, no gene knockout), they still performed a superior role in nitrate reduction (Figure 3A–C). Similarly, the DNRA process was stepwise, with no dramatic fluctuations in TOC concentration (Figure S11). The sterilized S. oneidensis@FeS system was deprived of the ability to electrosynthesize ammonia, suggesting that the nitrate reduction was attributed to S. oneidensis rather than FeS NPs. Considering that CymA served as an important electron transfer hub in the reversed EET, ΔcymA exhibited negligible nitrate reduction activity. (11,28) Furthermore, paralogs (e.g., MtrF) somewhat compensated for the absence of OmcA and MtrC, enabling ΔomcA/mrtC to have a complete EET chain, although their selectivity (33.4%) and NH4+-N production rate (123.8 μg·h–1·L reactor–1) were considerably lower than those of the wild type (S. oneidensis without any knockout processing) (Figure 3D). On the other hand, ΔomcA/mrtC-FeS and ΔcymA-FeS mutant strains biohybrid systems exhibited an unexpectedly substantial ammonia synthesis performance (selectivity: 97.1 and 39.2%, NH4+-N production rate: 103.7 and 202.3 μg·h–1·L reactor–1). Generally, CymA protein has been always viewed as the indispensable hub to the EET process in S. oneidensis MR-1, especially in outward electron transfer. (29) However, the ΔcymA-FeS biohydrid system exhibited satisfactory ammonia production performance without CymA protein involvement, which directly demonstrated that the artificial conduits constructed by FeS NPs were able to carry out inward electron transfer from the cathode to the targeted proteins (NapA, NapB, and NrfA) located in periplasmic space.
Figure 3
Figure 3. Nitrate reduction was by different mutants. (A) NO3–-N, (B) NO2–-N, and (C) NH4+-N concentrations. (D) Yield assessment. Each experiment was performed in triplicate, and error bars indicate the standard deviation.
Cathodic Electron Consumption
The current density was recorded under the constant potential for three cycles and is plotted in Figure 4A,C. The fluctuating current density indicated a reduction reaction occurring on the cathode biofilm. Initially, sufficient electron acceptors resulted in a gradual electron augmentation. Subsequently, the contradiction between the diminishing reduced substance supply to the electrode and the high electron feed progressively weakened the current density. (30) The S. oneidensis@FeS system had a greater average current density (−0.36 A/m2) in three cycles than that in S. oneidensis (−0.27 A/m2). The total cumulative coulomb amount was determined by integrating the current–time curve (Figure 4B,D). The prolonged reaction time allowed S. oneidensis to have more accumulated electrons (416.0 vs 329.8 A·s). However, the inferior bioelectrochemical reduction capacity resulted in an average cathode efficiency of only 46.5%, much less than that of the S. oneidensis@FeS system (65.4%) (Figure 4E). In Figure 4F, a comparison of ammonia production in different MES systems using nitrate as an electron acceptor is presented. This study stands out as it achieved the most remarkable performance in ammonia production, boasting a superior selectivity of 98.0% and a cathode efficiency of 65.4%, surpassing the results of previous studies. (11,31−35) When N2 was the electron acceptor, this work is even more superior. When activated sludge from a wastewater treatment plant was used as the biocatalyst, the selectivity was reported up to 9.62% (this work was 98.0%). (36) Furthermore, in another study, where long-term domesticated electroactive microorganisms were used to form cathodic biofilms, the cathode efficiency was 4.21% and the NH4+-N production rate was 0.252 μg·h–1·cm–2, only 23.3% of this work (1.081 μg·h–1·cm–2). (37) Although pure bacteria (Pseudomonas stutzeri) improved the cathodic efficiency to some extent (15%), there was a considerable gap compared to nitrate as an electron acceptor. (38)
Figure 4
Figure 4. Cathodic electron consumption in MES systems. Current density and coulomb in (A, B) S. oneidensis and (C, D) S. oneidensis@FeS systems. (E) Cathode efficiency and (F) a comparison of achievements.
In general, the trend of current density in the mutant strains was similar to that of the wild type (S. oneidensis without any knockout processing) (Figure 5A). The sterilized biohybrid system and ΔcymA maintained the current density at a low level and did not fluctuate due to the lack of biocatalysts as well as the intact EET chain, respectively. Correspondingly, the accumulated electrons for sterilized and ΔcymA were 0.3 and 1.5 A·s, which was considerably insufficient for nitrate reduction (Figure 5B). Compared to ΔcymA, ΔomcA/mrtC accumulated more electrons (107.1 A·s). The biosynthesized FeS NPs dramatically enhanced the electron uptake by different mutant strains, with ΔomcA/mrtC-FeS and ΔcymA-FeS values of 209.0 and 117.4 A·s. The current study revealed that the presence of paralogous (MtrF) resulted in the deletion of OmcA and MtrC not significantly affecting EET. (39) In the ΔomcA/mrtC-FeS system, FeS NPs not only compensated for their deficient function but also exhibited superiority over the wild-type strain (S. oneidensis without any knockout processing). In addition, this work illustrated that CymA was not indispensable in the inward EET when biologically self-assembled transmembrane electron conduits (FeS NPs) were available. Regarding electron utilization efficiency, the biohybrid systems likewise played a massive positive role (Figure 5C). The cathode efficiency of ΔomcA/mrtC-FeS was 54.9%, which was 17.9% higher than that of ΔomcA/mrtC, while the cathode efficiency of ΔcymA-FeS (44.4%) was also as 24.7-fold high as that of ΔcymA (1.8%).
Figure 5
Figure 5. Cathodic electron consumption by different mutants. (A) Current density, (B) Coulomb. (C) Cathode efficiency.
Electrochemical Analysis
At the beginning and end of experiments, the biocathode was evaluated by CV and EIS to study the evolution of electrochemical properties during three cycles. CV indicates the electron transfer between the cathode and the biofilm. (40) The curves displayed a characteristic sigmoidal shape, implying superior bioelectrocatalysis in the presence of electron acceptors (Figure 6A,E). The midpoint potential, denoted as E0′, could be employed to characterize the involvement of c-type cytochromes (c-Cyts) and electron shuttles in bioelectrochemistry. It was calculated as E0′ = (Ered + Eox)/2, where Ered and Eox represent the potentials corresponding to the reduction and oxidation peaks, respectively. (41,42) Between −800 and 600 mV applied potential, the S. oneidensis@FeS system displayed one more pair of redox peaks (E2 = 220 mV vs Ag/AgCl) than S. oneidensis (E1 = −320 mV vs Ag/AgCl). In particular, E1 and E2 were attributed to the flavin/c-Cyts combination and c-Cyts, correspondingly. (43−46) The immobilized biofilm cultivation method resulted in tighter contact between the biofilm and the electrode. Therefore, it did not require flavin as an electron shuttle to mediate electron transfer as in our previous study. (11) Moreover, FeS NPs activated more electroactive proteins (c-Cyts) and engaged them in cathodic electron uptake. The respective characteristic peak currents of S. oneidensis and S. oneidensis@FeS systems progressively increased over three cycles, individually suggesting a determining function of the flavin/c-Cyts combination and the c-Cyts in the EET. Larger CV curve areas (capacitance) reflected a stronger ability to store electrons (Figure 6B,F). The capacitances of S. oneidensis and S. oneidensis@FeS systems were improved from 0.58 and 1.56 mF to 0.70 and 1.71 mF, respectively. Because of their reaction cycles (15 and 9 days), the S. oneidensis@FeS system had a significantly higher capacitance accumulation rate, which could not be achieved without more activated c-Cyts.
Figure 6
Figure 6. Electrochemical analysis in MES systems. Cyclic voltammetry curves, capacitance, Nyquist plots of electrochemical impedance spectroscopy, and the values of the Rs and Rct in (A–D) S. oneidensis and (E–H) S. oneidensis@FeS systems.
EIS was performed to analyze the microbial electrochemical system composition and the properties during electrode reactions. (47) S. oneidensis and S. oneidensis@FeS systems both displayed typical Nyquist plots, which manifested as a semicircle and a diagonal line (Figure 6C,G). Figure 6D and H illustrates that in S. oneidensis and S. oneidensis@FeS systems, the ohmic resistance (Rs) remained stable, varying from 13.8 to 13.3 Ω and from 15.9 to 14.2 Ω, correspondingly. On the other hand, their initial charge transfer resistances (Rct) were 26.8 and 5.2 Ω, attributed to the high conductivity of FeS NPs, making the charge transfer accessible and further minimizing ohmic polarization (Figure S3). The high conductivity of FeS NPs allowed the electron transfer not to be restricted by the distance within a specific range, which prevented the perishing of the outer biofilm that was difficult to obtain electron. Thus, S. oneidensis@FeS biofilms had more contact area with the cathode, which resulted in more efficient electron utilization (Figure S5). Moreover, the enhanced catalytic rate led to a reduction in activation polarization of S. oneidensis@FeS system (Figure 2C,D). (48) These reasons contributed to a higher cathode efficiency in the S. oneidensis@FeS system (Figure 4E). Naturally, a portion of the electrons was consumed due to concentration polarization and biomass maintenance and growth in both systems. (49,50) Due to the spatial structure, the limited contact area between the flexible cells and rigid solid electrodes in Shewanella bacteria limited the EET efficiency. FeS NPs activated idle electroactive proteins so as to enhance the interfacial electron transfer efficiency, which was reflected by prominent redox peaks, high capacitance, and low electron transfer resistance.
Molecular-Level Analysis for Surface Group and Electroactivity
Electrochemical in-situ Fourier transform infrared spectra revealed an external redox protein phase transition behavior involved during the EET process at the molecular level. The combined change in gradient potential and chemical band implied a redox reaction between biofilm and electrode and a protein molecular conformation transition (Figure 7). (51) At 1201, 1558, and 1683 cm–1, the intensity continuously escalated with the applied potential from −0.9 to 0.4 V, corresponding to the polarization of c-Cyts, C–N group in amide II, and C═O group in amide I, respectively. (52) As polarization intensity was proportional to the relative dielectric constant, the FeS NPs rendered S. oneidensis with more substantial electron storage capacity to participate in extracellular respiration. (53,54) This corroborated the previous remarks that the S. oneidensis@FeS system had a greater capacitance. (55) As demonstrated in our previous work, c-Cyts, as a typical electroactive protein, played an electron transfer role in reversing EET. (11) As a protein-like substance, the amide group could also act as a momentous electron transfer site first discovered in MES of ammonia. (56) It was reported that an applied electric potential could induce amide group polarization and provide a motive force for electron hopping between proteins, in which the amide group could function as a relay station for electron transfer. (57) C–N and C═O were essential active sites in protein-like substances involved in electron transfer. For example, after polarization, the electrons around the N and O atoms move away from the corresponding nuclear state and into higher energy states, which would facilitate electron transfer. In addition, C═O could accept protons to form ·C–O–H resulting in the electron transfer. (58) Consequently, the polarized amide groups and c-Cyts on the cell surface meant that more electrons in higher energy states could be transferred through protein-like substances and electroactive proteins.
Figure 7
Figure 7. Electrochemical in-situ Fourier transform infrared spectra in (A) S. oneidensis and (B) S. oneidensis@FeS systems.
Proposed Mechanism
Based on these above results, the mechanism was proposed as the following three pathways (Figure 8). Besides the proven reversed Mtr pathway (the first pathway), biological self-assembled transmembrane electron conduits (FeS NPs) could likewise transfer electrons from the extracellular to the intracellular environment, and electrons were ultimately distributed to NapA, NapB, and NrfA without CymA, resulting in the DNRA process (the second pathway). (11) Furthermore, the amide group in protein-like substances facilitated electron transfer in the outer membrane (the third pathway). Although the role of protein-like substances in S. oneidensis in electron transfer has not been explicitly stated, Okamoto et al. demonstrated that proteins distinct from the outer membrane cytochrome c complex (MtrCBA) couple proton transport with EET to maintain charge neutrality in the periplasm. (59) Considering the H+-consuming DNRA process, these proteins are similarly likely to bind proton transport in the inward EET. Nevertheless, it was necessary to investigate further whether electrons directly interacted with nitrate reductase and nitrite reductase or entered into the cellular menaquinone pool and reacted with one or more inner membrane cytochromes, permitting electrons to flow into existing electron transfer chain compositions and eventually into reductase in the periplasmic space. Moreover, due to insufficient genes coded for c-Cyts and the absence of conductive pilus-like structures, S. oneidensis exhibited deficiencies in outward and inward EET. (60) The hybrid system allowed more c-Cyts to operate, and functionally, FeS NPs were similar to type IV pili. Hence, the “bionic type IV pili” compensated for the congenital losses in S. oneidensis MR-1.
Figure 8
Figure 8. Schematic illustration of the mechanism. OmcA and MtrC, extracellular iron oxide respiratory system surface decaheme cytochrome c component; MtrB, extracellular iron oxide respiratory system outer membrane component; MtrA, extracellular iron oxide respiratory system periplasmic decaheme cytochrome c component; CymA, membrane anchored tetraheme c; MQ, menaquinone; MQH2, reduced form of menaquinone; NapB, periplasmic nitrate reductase cytochrome c subunit; NapA, periplasmic nitrate reductase molybdopterin-binding subunit; NrfA, ammonia-forming nitrite reductase.
Implications
The contradiction between chemical reaction kinetics and thermodynamics leads to an unsatisfactory energy conversion efficiency in the Haber-Bosch process (10–20%). (61) Ammonia could be synthesized sustainably and efficiently by reducing contaminant nitrate via renewable electricity as an energy source with the electrotroph S. oneidensis as a biocatalyst. For renewable electricity, the minimal theoretical energy consumption is roughly 60% of the traditional methane-based Haber–Bosch technology. (62) In 2017, the weighted average cost of renewable electricity globally dropped within the range of fossil fuels, i.e., between $0.047 and $0.167 per kWh. (63) From 2010 to 2017, utility-scale solar and onshore wind electricity prices have declined by 73 and 23% to $0.1 per kWh and $0.06 per kWh, respectively. (64) With these latest advances and the declining cost of renewable energy production, it creates opportunities for sustainable NH3 synthesis pathways to compete with the prevailing Haber–Bosch technology in future markets. Furthermore, when electricity prices fall below 4 cents per kWh and energy conversion efficiencies achieve at least 60%, electrochemical production is comparable in cost to traditional fossil fuel-derived processes. (64) However, the limited electron transfer between interfaces restricts the cathode efficiency (33.1%) and selectivity (82.5%). (11) Inspired by biomineralization, the hybrid system based on microorganisms and nanomaterials is an attractive intersection and emerging direction for biology and materials science, combining self-repair and catalytic activities, respectively. (65) Remarkable dispersion structure, high surface energy, and strong biocompatibility significantly improve the stability relative to artificial counterparts, indicating effective, economical, and sustainable application prospects. (27) Herein, the biohybrid system effectively breaks the electron transfer limitation for natural bacteria and improves the cathode efficiency and selectivity to an unprecedented maximum of 65.4 and 98.0% in MES of ammonia. In addition to S. oneidensis, sulfate-reducing bacteria lacking outer-membrane cytochromes and electron mediators could also biosynthesize FeS NPs to achieve EET, significantly improving the applicability of the biohybrid system. (66) This work may improve our comprehension of the interconnection between semiconductor materials and bacteria and contribute to exploring new EET proteins. For MES technology, which is just in its infancy in research, achieving this goal still requires continuous efforts.
Supporting Information
Click to copy section linkSection link copied!
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.est.3c10897.
Photographs of biosynthesized FeS in wild-type and mutant strains; Fe(II) concentration, UV–vis-NIR absorption spectra, and electrochemical characteristics (CV, capacitance, Nyquist plots, and the values of Rs and Rct) in the optimizing biosynthesized-FeS NPs experiments; CLSM images of S. oneidensis and S. oneidensis@FeS biofilm; SEM and EDS mapping images of S. oneidensis and S. oneidensis@FeS; HAADF-STEM and EDS mapping images of the sliced mutant strains-FeS; TOC concentration in S. oneidensis, S. oneidensis@FeS, mutant strains, and mutant strains-FeS systems; schematic diagram and the composition of electrolyte solution in MES system (Figures S1–S11 and Table S1) (PDF)
Terms & Conditions
Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.
Author Information
Click to copy section linkSection link copied!
- Sen Qiao - Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian116024, P.R. China;
https://orcid.org/0000-0001-7543-7766;
- Guangfei Liu - Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian116024, P.R. China;https://orcid.org/0000-0001-9514-3271
Acknowledgments
Click to copy section linkSection link copied!
The authors deeply appreciate Prof. Kenneth Nealson (University of Southern California) for kindly providing us MR-1 and related mutant strains. This work was supported by the National Natural Science Foundation of China (No. 22176026); the National Key Research and Development Project (2019YFA0705804).
References
Click to copy section linkSection link copied!
This article references 66 other publications.
- 1Hollevoet, L.; Jardali, F.; Gorbanev, Y.; Creel, J.; Bogaerts, A.; Martens, J. A. Towards Green Ammonia Synthesis through Plasma-Driven Nitrogen Oxidation and Catalytic Reduction. Angew. Chem. 2020, 132 (52), 24033– 24037, DOI: 10.1002/ange.202011676Google ScholarThere is no corresponding record for this reference.
- 2Jabarivelisdeh, B.; Jin, E.; Christopher, P.; Masanet, E. Model-Based Analysis of Ammonia Production Processes for Quantifying Energy Use, Emissions, and Reduction Potentials. ACS Sustain. Chem. Eng. 2022, 10 (49), 16280– 16289, DOI: 10.1021/acssuschemeng.2c04976Google ScholarThere is no corresponding record for this reference.
- 3Soloveichik, G. Electrochemical Synthesis of Ammonia as a Potential Alternative to the Haber–Bosch Process. Nat. Catal. 2019, 2 (5), 377– 380, DOI: 10.1038/s41929-019-0280-0Google Scholar3https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXpvVyqs7g%253D&md5=c06dc4f19fadfe8b694d2cb938c0cb1fElectrochemical synthesis of ammonia as a potential alternative to the Haber-Bosch processSoloveichik, GrigoriiNature Catalysis (2019), 2 (5), 377-380CODEN: NCAACP; ISSN:2520-1158. (Nature Research)The preeminent Haber-Bosch process has been feeding humankind for more than one hundred years. Are electrochem. pathways for ammonia synthesis able to compete with it in the future. Electrocatalysts, electrolytes and novel cell design may be key.
- 4Nayak-Luke, R. M.; Bañares-Alcántara, R. Techno-Economic Viability of Islanded Green Ammonia as a Carbon-Free Energy Vector and as a Substitute for Conventional Production. Energy Environ. Sci. 2020, 13 (9), 2957– 2966, DOI: 10.1039/D0EE01707HGoogle Scholar4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtlKku7rI&md5=77d56b4b05ee524beb3f85e763278ff7Techno-economic viability of islanded green ammonia as a carbon-free energy vector and as a substitute for conventional productionNayak-Luke, Richard Michael; Banares-Alcantara, ReneEnergy & Environmental Science (2020), 13 (9), 2957-2966CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)Decarbonising ammonia prodn. is an environmental imperative given that it independently accounts for 1.8% of global carbon dioxide emissions and supports the feeding of over 48% of the global population. The recent decline of prodn. costs and its potential as an energy vector warrant investigation of whether green ammonia prodn. is com. competitive. Considering 534 locations in 70 countries and designing and operating the islanded prodn. process to minimise the levelised cost of ammonia (LCOA) at each, we show the range of achievable LCOA, the cost of process flexibility, the components of LCOA, and therein the scope of LCOA redn. achievable at present and in 2030. These results are benchmarked against ammonia spot prices, cost per GJ of refined fuels and the LCOE of alternative energy storage methods. Currently a LCOA of $473 t-1 is achievable, at the best locations the required process flexibility increases the achievable LCOA by 56%; the electrolyzer CAPEX and operation are the most significant costs. By 2030, $310 t-1 is predicted to be achievable with multiple locations below $350 t-1. At $25.4 GJ-1 currently and $16.6 GJ-1 by 2030 prior combustion, this compares favorably against other refined fuels such as kerosene ($8.7-18.3 GJ-1) that do not have the benefit of being carbon-free.
- 5Bennaamane, S.; Rialland, B.; Khrouz, L.; Fustier-Boutignon, M.; Bucher, C.; Clot, E.; Mézailles, N. Ammonia Synthesis at Room Temperature and Atmospheric Pressure from N2: A Boron-Radical Approach. Angew. Chem. 2023, 135 (3), e202209102 DOI: 10.1002/ange.202209102Google ScholarThere is no corresponding record for this reference.
- 6He, W.; Zhang, J.; Dieckhöfer, S.; Varhade, S.; Brix, A. C.; Lielpetere, A.; Seisel, S.; Junqueira, J. R. C.; Schuhmann, W. Splicing the Active Phases of Copper/Cobalt-Based Catalysts Achieves High-Rate Tandem Electroreduction of Nitrate to Ammonia. Nat. Commun. 2022, 13 (1), 1129, DOI: 10.1038/s41467-022-28728-4Google Scholar6https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xls1Onsrs%253D&md5=c8773c74f69432802d06addeee800c4fSplicing the active phases of copper/cobalt-based catalysts achieves high-rate tandem electroreduction of nitrate to ammoniaHe, Wenhui; Zhang, Jian; Dieckhoefer, Stefan; Varhade, Swapnil; Brix, Ann Cathrin; Lielpetere, Anna; Seisel, Sabine; Junqueira, Joao R. C.; Schuhmann, WolfgangNature Communications (2022), 13 (1), 1129CODEN: NCAOBW; ISSN:2041-1723. (Nature Portfolio)Electrocatalytic recycling of waste nitrate (NO3-) to valuable ammonia (NH3) at ambient conditions is a green and appealing alternative to the Haber-Bosch process. However, the reaction requires multi-step electron and proton transfer, making it a grand challenge to drive high-rate NH3 synthesis in an energy-efficient way. Herein, we present a design concept of tandem catalysts, which involves coupling intermediate phases of different transition metals, existing at low applied overpotentials, as cooperative active sites that enable cascade NO3--to-NH3 conversion, in turn avoiding the generally encountered scaling relations. We implement the concept by electrochem. transformation of Cu-Co binary sulfides into potential-dependent core-shell Cu/CuOx and Co/CoO phases. Electrochem. evaluation, kinetic studies, and in-situ Raman spectra reveal that the inner Cu/CuOx phases preferentially catalyze NO3- redn. to NO2-, which is rapidly reduced to NH3 at the nearby Co/CoO shell. This unique tandem catalyst system leads to a NO3--to-NH3 Faradaic efficiency of 93.3 ± 2.1% in a wide range of NO3- concns. at pH 13, a high NH3 yield rate of 1.17 mmol cm-2 h-1 in 0.1 M NO3- at -0.175 V vs. RHE, and a half-cell energy efficiency of ∼36%, surpassing most previous reports.
- 7Teng, J.; Deng, Y.; Zhou, X.; Yang, W.; Huang, Z.; Zhang, H.; Zhang, M.; Lin, H. A Critical Review on Thermodynamic Mechanisms of Membrane Fouling in Membrane-Based Water Treatment Process. Front. Environ. Sci. Eng. 2023, 17 (10), 129, DOI: 10.1007/s11783-023-1729-6Google ScholarThere is no corresponding record for this reference.
- 8Hemond, H. F.; Lin, K. Nitrate Suppresses Internal Phosphorus Loading in an Eutrophic Lake. Water Res. 2010, 44 (12), 3645– 3650, DOI: 10.1016/j.watres.2010.04.018Google ScholarThere is no corresponding record for this reference.
- 9Yan, J.; Xu, H.; Chang, L.; Lin, A.; Cheng, D. Revealing the pH-Dependent Mechanism of Nitrate Electrochemical Reduction to Ammonia on Single-Atom Catalysts. Nanoscale 2022, 14 (41), 15422– 15431, DOI: 10.1039/D2NR02545KGoogle ScholarThere is no corresponding record for this reference.
- 10Sheldon, R. A.; Woodley, J. M. Role of Biocatalysis in Sustainable Chemistry. Chem. Rev. 2018, 118 (2), 801– 838, DOI: 10.1021/acs.chemrev.7b00203Google Scholar10https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsVeqt73P&md5=f38e1ba13fb6bd8626751cbd31af8b8fRole of Biocatalysis in Sustainable ChemistrySheldon, Roger A.; Woodley, John M.Chemical Reviews (Washington, DC, United States) (2018), 118 (2), 801-838CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)A review. Based on the principles and metrics of green chem. and sustainable development, biocatalysis is both a green and sustainable technol. This is largely a result of the spectacular advances in mol. biol. and biotechnol. achieved in the last two decades. Protein engineering has enabled the optimization of existing enzymes and the invention of entirely new biocatalytic reactions that were previously unknown in Nature. It is now eminently feasible to develop enzymic transformations to fit predefined parameters, resulting in processes that are truly sustainable by design. This has successfully been applied, for example, in the industrial synthesis of active pharmaceutical ingredients. In addn. to the use of protein engineering, other aspects of biocatalysis engineering, such as substrate, medium and reactor engineering, can be utilized to improve the efficiency, cost-effectiveness and, hence, the sustainability of biocatalytic reactions. Furthermore, immobilization of an enzyme can improve its stability and enable its reuse multiple times, resulting in a better performance and com. viability. Consequently, biocatalysis is being widely applied in the prodn. of pharmaceuticals and in some commodity chems. Moreover, its broader application will be further stimulated in the future by the emerging biobased economy.
- 11Li, Y.; Qiao, S.; Guo, M.; Hou, C.; Wang, J.; Yu, C.; Zhou, J.; Quan, X. Microbial Electrosynthetic Nitrate Reduction to Ammonia by Reversing the Typical Electron Transfer Pathway in Shewanella oneidensis. Cell Rep. Phys. Sci. 2023, 4 (6), 101433 DOI: 10.1016/j.xcrp.2023.101433Google ScholarThere is no corresponding record for this reference.
- 12Schwalb, C.; Chapman, S. K.; Reid, G. A. The Membrane-Bound Tetrahaem c-Type Cytochrome Cym A Interacts Directly with the Soluble Fumarate Reductase in Shewanella. Biochem. Soc. Trans. 2002, 30 (4), 658– 662, DOI: 10.1042/bst0300658Google ScholarThere is no corresponding record for this reference.
- 13Yu, Y.-Y.; Wang, Y.-Z.; Fang, Z.; Shi, Y.-T.; Cheng, Q.-W.; Chen, Y.-X.; Shi, W.; Yong, Y.-C. Single Cell Electron Collectors for Highly Efficient Wiring-up Electronic Abiotic/Biotic Interfaces. Nat. Commun. 2020, 11 (1), 4087, DOI: 10.1038/s41467-020-17897-9Google Scholar13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhs1Crtr7L&md5=0d95f39117becf6348de710549a6b46eSingle cell electron collectors for highly efficient wiring-up electronic abiotic/biotic interfacesYu, Yang-Yang; Wang, Yan-Zhai; Fang, Zhen; Shi, Yu-Tong; Cheng, Qian-Wen; Chen, Yu-Xuan; Shi, Weidong; Yong, Yang-ChunNature Communications (2020), 11 (1), 4087CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)By electronically wiring-up living cells with abiotic conductive surfaces, bioelectrochem. systems (BES) harvest energy and synthesize elec.-/solar-chems. with unmatched thermodn. efficiency. However, the establishment of an efficient electronic interface between living cells and abiotic surfaces is hindered due to the requirement of extremely close contact and high interfacial area, which is quite challenging for cell and material engineering. Herein, we propose a new concept of a single cell electron collector, which is in-situ built with an interconnected intact conductive layer on and cross the individual cell membrane. The single cell electron collector forms intimate contact with the cellular electron transfer machinery and maximizes the interfacial area, achieving record-high interfacial electron transfer efficiency and BES performance. Thus, this single cell electron collector provides a superior tool to wire living cells with abiotic surfaces at the single-cell level and adds new dimensions for abiotic/biotic interface engineering.
- 14Beinert, H. Iron-Sulfur Proteins: Ancient Structures, Still Full of Surprises. JBIC J. Biol. Inorg. Chem. 2000, 5 (1), 2– 15, DOI: 10.1007/s007750050002Google Scholar14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXitVyktb4%253D&md5=43d370fa3f991c4bb303d092ea614f5bIron-sulfur proteins: ancient structures, still full of surprisesBeinert, HelmutJBIC, Journal of Biological Inorganic Chemistry (2000), 5 (1), 2-15CODEN: JJBCFA; ISSN:0949-8257. (Springer-Verlag)A review with 59 refs. The properties and functions of Fe-S proteins are surveyed under the following headings: S and Fe; Fe-S clusters; evolution of cofactor use; early observations; complex and extended clusters; S-exchange and core interconversions; synthesis and biosynthesis of Fe-S clusters; functions of Fe-S clusters: electron transfer, electron delocalization, spin states and magnetism, covalency of S bonds; non-electron transfer functions of Fe-S clusters: substrate binding and catalysis, and regulatory and sensing functions.
- 15Han, Y.; Liao, C.; Meng, X.; Zhao, Q.; Yan, X.; Tian, L.; Liu, Y.; Li, N.; Wang, X. Switchover of Electrotrophic and Heterotrophic Respirations Enables the Biomonitoring of Low Concentration of BOD in Oxygen-Rich Environment. Water Res. 2023, 235, 119897 DOI: 10.1016/j.watres.2023.119897Google Scholar15https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXmt1ahtrs%253D&md5=85861cb405fa873a43313efc1ee23a7aSwitchover of electrotrophic and heterotrophic respirations enables the biomonitoring of low concentration of BOD in oxygen-rich environmentHan, Yilian; Liao, Chengmei; Meng, Xinyi; Zhao, Qian; Yan, Xuejun; Tian, Lili; Liu, Ying; Li, Nan; Wang, XinWater Research (2023), 235 (), 119897CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)BOD (BOD) is a key indicator of water quality. However, there is still no technique to directly measure BOD at low concns. in oxygen-rich environments. Here, we propose a new scheme using facultative electrotrophs as the sensing element, and confirmed aerobic Acinetobacter venetianus RAG-1 immobilized on electrode was able to measure BOD via the switchover between electrotrophic and heterotrophic respirations. The hybrid binder of Nafion and polytetrafluoroethylene (PTFE) maximized the baseline current (127 ± 2 A/m2) and sensitivity (2.5 ± 0.1 (mA/m2)/(mg/L)). The current decrease and the BOD5 concn. fitted well with a linear model in the case of known contaminants, verified with both lab samples of acetate and glucose (R2>0.96) and in std. curves of real environmental samples collected from the lake and the effluent of wastewater treatment plant (R2>0.98). Importantly, the biosensor tested actual contaminated water samples with an error of 0.4∼10% compared to BOD5 in the case of unknown contaminants. Transcriptomics revealed that reverse oxidative TCA may involve in the electrotrophic respiration of RAG-1 since citrate synthase (gltA) was highly expressed, which was partly downregulated when heterotrophic metab. was triggered by BOD. This can be returned to electrotroph when BOD was depleted. Our results showed a new way to rapidly measure BOD in oxygen-rich environment, demonstrating the possibility to employ bacteria with two competitive respiration pathways for pollution detection.
- 16Yang, W.; Zhou, M.; Oturan, N.; Bechelany, M.; Cretin, M.; Oturan, M. A. Highly Efficient and Stable FeIIFeIII LDH Carbon Felt Cathode for Removal of Pharmaceutical Ofloxacin at Neutral pH. J. Hazard. Mater. 2020, 393, 122513 DOI: 10.1016/j.jhazmat.2020.122513Google Scholar16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXltF2nsr0%253D&md5=341e78b12d2b16e83f29184922064ab1Highly efficient and stable FeIIFeIII LDH carbon felt cathode for removal of pharmaceutical ofloxacin at neutral pHYang, Weilu; Zhou, Minghua; Oturan, Nihal; Bechelany, Mikhael; Cretin, Marc; Oturan, Mehmet A.Journal of Hazardous Materials (2020), 393 (), 122513CODEN: JHMAD9; ISSN:0304-3894. (Elsevier B.V.)The traditional electro-Fenton (EF) has been facing major challenges including narrow suitable range of pH and non-reusability of catalyst. To overcome these drawbacks we synthesized FeIIFeIII-layered double hydroxide modified carbon felt (FeIIFeIII LDH-CF) cathode via in situ solvo-thermal process. Chem. compn. and electrochem. characterization of FeIIFeIII LDH-CF were tested and analyzed. The apparent rate const. of decay kinetics of ofloxacin (OFC) with FeIIFeIII LDH-CF (0.18 min-1) at pH 7 was more than 3 times higher than that of homogeneous EF (0.05 min-1) at pH 3 with 0.1 mM Fe2+ under same c.d. (9.37 mA cm-2). Also, a series of expts. including evolution of soln. pH, iron leaching, OFC removal with trapping agent and quant. detection of hydroxyl radicals (·OH) were conducted, demonstrating the dominant role of ·OH generated by surface catalyst via ≃ FeII/FeIII on LDH cathode for degrdn. of orgs. as well contributing to high efficiency and good stability at neutral pH. Besides, formation and evolution of arom. intermediates, carboxylic acids and inorg. ions (F-, NH4+ and NO3-) were identified by High-Performance Liq. chromatog., Gas Chromatog.-Mass Spectrometry and ionic chromatog. analyses. These findings allowed proposing a plausible degrdn. pathway of OFC by ·OH generated in the heterogeneous EF process.
- 17Jiao, K.; Xuan, J.; Du, Q.; Bao, Z.; Xie, B.; Wang, B.; Zhao, Y.; Fan, L.; Wang, H.; Hou, Z.; Huo, S.; Brandon, N. P.; Yin, Y.; Guiver, M. D. Designing the next Generation of Proton-Exchange Membrane Fuel Cells. Nature 2021, 595 (7867), 361– 369, DOI: 10.1038/s41586-021-03482-7Google Scholar17https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhsFGqtrvL&md5=a1626e0aeec3bf0d0e3daecced15ba35Designing the next generation of proton-exchange membrane fuel cellsJiao, Kui; Xuan, Jin; Du, Qing; Bao, Zhiming; Xie, Biao; Wang, Bowen; Zhao, Yan; Fan, Linhao; Wang, Huizhi; Hou, Zhongjun; Huo, Sen; Brandon, Nigel P.; Yin, Yan; Guiver, Michael D.Nature (London, United Kingdom) (2021), 595 (7867), 361-369CODEN: NATUAS; ISSN:0028-0836. (Nature Portfolio)Abstr.: With the rapid growth and development of proton-exchange membrane fuel cell (PEMFC) technol., there has been increasing demand for clean and sustainable global energy applications. Of the many device-level and infrastructure challenges that need to be overcome before wide commercialization can be realized, one of the most crit. ones is increasing the PEMFC power d., and ambitious goals have been proposed globally. For example, the short- and long-term power d. goals of Japan's New Energy and Industrial Technol. Development Organization are 6 kW per L by 2030 and 9 kW per L by 2040, resp. To this end, here we propose tech. development directions for next-generation high-power-d. PEMFCs. We present the latest ideas for improvements in the membrane electrode assembly and its components with regard to water and thermal management and materials. These concepts are expected to be implemented in next-generation PEMFCs to achieve high power d.
- 18Kempers, A. J.; Zweers, A. Ammonium Determination in Soil Extracts by the Salicylate Method. Commun. Soil Sci. Plant Anal. 1986, 17 (7), 715– 723, DOI: 10.1080/00103628609367745Google ScholarThere is no corresponding record for this reference.
- 19Shinn, M. B. Colorimetric Method for Determination of Nitrate. Ind. Eng. Chem. Anal. Ed. 1941, 13 (1), 33– 35, DOI: 10.1021/i560089a010Google Scholar19https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaH3MXosV2l&md5=02c42c7720ecec925a8029f3d4e6697aColorimetric method for determination of nitriteShinn, Martha B.Industrial and Engineering Chemistry, Analytical Edition (1941), 13 (), 33-5CODEN: IENAAD; ISSN:0096-4484.Sulfanilamide in 0.2% aq. soln. and a 0.1% aq. soln. (I) of N-(1-naphthyl)ethylenediamine dihydrochloride are superior to sulfanilic acid and α-naphthylamine for the colorimetric detn. of nitrite. The color is clearer, reaches its max. more rapidly and remains stable for a longer time. A standardized soln. of sulfanilamide is substituted for NaNO2 as a primary standard. The soln. for analysis can be neutral or up to 1 N in acid. Not more than 0.05 mg. of nitrite should be present and the vol. not over 35 ml. To the unknown add 1 ml. of 6 N HCl, 5 ml. of the sulfanilamide soln. and allow to stand 3 min. Add 1 ml. of 0.5% soln. of NH4 sulfamate and let stand 2 min. Then add 1 ml. of I and dil. to exactly 50 ml. and mix. At the same time prep. a nitrite standard from the sulfanilamide soln. by reduction with NaNO3 in dil. HCl.
- 20Fu, X.-Z.; Li, J.; Pan, X.-R.; Huang, L.; Li, C.-X.; Cui, S.; Liu, H.-Q.; Tan, Z.-L.; Li, W.-W. A Single Microbial Electrochemical System for CO2 Reduction and Simultaneous Biogas Purification. Upgrading and Sulfur Recovery. Bioresour. Technol. 2020, 297, 122448 DOI: 10.1016/j.biortech.2019.122448Google ScholarThere is no corresponding record for this reference.
- 21Yu, Y.-Y.; Cheng, Q.-W.; Sha, C.; Chen, Y.-X.; Naraginti, S.; Yong, Y.-C. Size-Controlled Biosynthesis of FeS Nanoparticles for Efficient Removal of Aqueous Cr(VI). Chem. Eng. J. 2020, 379, 122404 DOI: 10.1016/j.cej.2019.122404Google Scholar21https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsFKhtL%252FL&md5=516d08d7b236c9c535f1b01a36189815Size-controlled biosynthesis of FeS nanoparticles for efficient removal of aqueous Cr(VI)Yu, Yang-Yang; Cheng, Qian-Wen; Sha, Chong; Chen, Yu-Xuan; Naraginti, Saraschandra; Yong, Yang-ChunChemical Engineering Journal (Amsterdam, Netherlands) (2020), 379 (), 122404CODEN: CMEJAJ; ISSN:1385-8947. (Elsevier B.V.)In this study, biogenic iron sulfide nanoparticles (FeS NPs) were synthesized by Shewanella and used for Cr(VI) removal. To control the size of FeS NPs, the biol. S(-II) releasing rate was proposed as the key parameter in Fe(III) redn. and was subtly tuned with the aid of a kinetic model. Field emission scanning electron microscope (FESEM) observation revealed that gradually increased S(-II) releasing rate lead to the formation of FeS NPs with size from 30 nm to 90 nm. Impressively, the biogenic FeS NPs with 30-40 nm showed high removal rate and large removal capacity (565.6 mg/g) for removal of aq. Cr(VI). Further analyses revealed that the improved performance of small FeS NPs was ascribed to the reduced passivation of FeS. Therefore, this study provided a facile approach for size-controlled biosynthesis of FeS NPs, and demonstrated the promise to use biogenic FeS NPs for chromate remediation.
- 22Zhou, C.; Zhou, Y.; Rittmann, B. E. Reductive Precipitation of Sulfate and Soluble Fe(III) by Desulfovibrio Vulgaris: Electron Donor Regulates Intracellular Electron Flow and Nano-FeS Crystallization. Water Res. 2017, 119, 91– 101, DOI: 10.1016/j.watres.2017.04.044Google Scholar22https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXmsFertbw%253D&md5=0621ade89585258bb4c276acba975c36Reductive precipitation of sulfate and soluble Fe(III) by Desulfovibrio vulgaris: Electron donor regulates intracellular electron flow and nano-FeS crystallizationZhou, Chen; Zhou, Yun; Rittmann, Bruce E.Water Research (2017), 119 (), 91-101CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)Fully understanding the metab. of SRB provides fundamental guidelines for allowing the microorganisms to provide more beneficial services in water treatment and resource recovery. The electron-transfer pathway of sulfate respiration by Desulfovibrio vulgaris is well studied, but still partly unresolved. Here we provide deeper insight by comprehensively monitoring metabolite changes during D. vulgaris metab. with two electron donors, lactate and pyruvate, in presence or absence of citrate-chelated sol. FeIII as an addnl. competing electron acceptor. H2 was produced from lactate oxidn. to pyruvate, but pyruvate oxidn. produced mostly formate. Accumulation of lactate-originated H2 during lag phases inhibited pyruvate transformation to acetate. Sulfate redn. was initiated by lactate-originated H2, but MQ-mediated e- flow initiated sulfate redn. without delay when pyruvate was the donor. When H2-induced electron flow gave priority to FeIII redn. over sulfate redn., the long lag phase before sulfate redn. shortened the time for iron-sulfide crystallite growth and led to smaller mackinawite (Fe1+xS) nanocrystallites. Synthesizing all the results, we propose that electron flow from lactate or pyruvate towards SO2-4 redn. to H2S are through at least three routes that are regulated by the e- donor (lactate or pyruvate) and the presence or absence of another e- acceptor (FeIII here). These routes are not competing, but complementary: e.g., H2 or formate prodn. and oxidn. were necessary for sulfite and disulfide/trisulfide redn. to sulfide. Our study suggests that the e- donor provides a practical tool to regulate and optimize SRB-predominant bioremediation systems.
- 23Fu, X.-Z.; Wu, J.; Cui, S.; Wang, X.-M.; Liu, H.-Q.; He, R.-L.; Yang, C.; Deng, X.; Tan, Z.-L.; Li, W.-W. Self-Regenerable Bio-Hybrid with Biogenic Ferrous Sulfide Nanoparticles for Treating High-Concentration Chromium-Containing Wastewater. Water Res. 2021, 206, 117731 DOI: 10.1016/j.watres.2021.117731Google Scholar23https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXitF2htbnF&md5=d7a03b122ee0f9f9b0284e9af2002df3Self-regenerable bio-hybrid with biogenic ferrous sulfide nanoparticles for treating high-concentration chromium-containing wastewaterFu, Xian-Zhong; Wu, Jie; Cui, Shuo; Wang, Xue-Meng; Liu, Hou-Qi; He, Ru-Li; Yang, Cheng; Deng, Xin; Tan, Zhou-Liang; Li, Wen-WeiWater Research (2021), 206 (), 117731CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)Biogenic ferrous sulfide nanoparticles (bio-FeS) as low-cost and green-synthesized nanomaterial are promising for heavy metals removal, but the need for complicated extn., storage processes and the prodn. of iron sludge still restrict their practical application. Here, a self-regenerable bio-hybrid consisting of bacterial cells and self-assembled bio-FeS was developed to efficiently remove chromium (Cr(VI)). A dense layer of bio-FeS was distributed on the cell surface and in the periplasmic space of Shewanella oneidensis MR-1, endowing the bacterium with good Cr(VI) tolerance and unusual activity for bio-FeS-mediated Cr(VI) redn. An artificial transmembrane electron channel was constituted by the bio-FeS to facilitate extracellular electron pumping, enabling efficient regeneration of extracellular bio-FeS for continuous Cr(VI) redn. The bio-hybrid maintained high activity within three consecutive treatment-regeneration cycles for treating both simulated Cr(VI)-contg. wastewater (50 mg/L) and real electroplating wastewater. Importantly, its activity can be facilely and fully restored through bio-FeS re-synthesis or regeneration with replenished fresh bacteria. Overall, the bio-hybrid merges the self-regeneration ability of bacteria with high activity of bio-FeS , opening a promising new avenue for sustainable treatment of heavy metal- contg. wastewater.
- 24Rowe, A. R.; Rajeev, P.; Jain, A.; Pirbadian, S.; Okamoto, A.; Jeffrey, A.; El-Naggar, Y.; Nealson, Kenneth H. Tracking Electron Uptake from a Cathode into Shewanella Cells: Implications for Energy Acquisition from Solid-Substrate Electron Donors. mBio 2018, 9 (1), e02203 DOI: 10.1128/mbio.02203-17Google ScholarThere is no corresponding record for this reference.
- 25Meshulam-Simon, G.; Behrens, S.; Choo, A. D.; Spormann, A. M. Hydrogen Metabolism in Shewanella oneidensis MR-1. Appl. Environ. Microbiol. 2007, 73 (4), 1153– 1165, DOI: 10.1128/AEM.01588-06Google Scholar25https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXitlyqsb0%253D&md5=5d70a37aab97fa74ecea36d46519313eHydrogen metabolism in Shewanella oneidensis MR-1Meshulam-Simon, Galit; Behrens, Sebastian; Choo, Alexander D.; Spormann, Alfred M.Applied and Environmental Microbiology (2007), 73 (4), 1153-1165CODEN: AEMIDF; ISSN:0099-2240. (American Society for Microbiology)Shewanella oneidensis MR-1 is a facultative sediment microorganism which uses diverse compds., such as oxygen and fumarate, as well as insol. Fe(III) and Mn(IV) as electron acceptors. The electron donor spectrum is more limited and includes metabolic end products of primary fermenting bacteria, such as lactate, formate, and hydrogen. While the utilization of hydrogen as an electron donor has been described previously, we report here the formation of hydrogen from pyruvate under anaerobic, stationary-phase conditions in the absence of an external electron acceptor. Genes for the two S. oneidensis MR-1 hydrogenases, hydA, encoding a periplasmic [Fe-Fe] hydrogenase, and hyaB, encoding a periplasmic [Ni-Fe] hydrogenase, were found to be expressed only under anaerobic conditions during early exponential growth and into stationary-phase growth. Analyses of ΔhydA, ΔhyaB, and ΔhydA ΔhyaB in-frame-deletion mutants indicated that HydA functions primarily as a hydrogen-forming hydrogenase while HyaB has a bifunctional role and represents the dominant hydrogenase activity under the exptl. conditions tested. Based on results from physiol. and genetic expts., we propose that hydrogen is formed from pyruvate by multiple parallel pathways, one pathway involving formate as an intermediate, pyruvate-formate lyase, and formate-hydrogen lyase, comprised of HydA hydrogenase and formate dehydrogenase, and a formate-independent pathway involving pyruvate dehydrogenase. A reverse electron transport chain is potentially involved in a formate-hydrogen lyase-independent pathway. While pyruvate does not support a fermentative mode of growth in this microorganism, pyruvate, in the absence of an electron acceptor, increased cell viability in anaerobic, stationary-phase cultures, suggesting a role in the survival of S. oneidensis MR-1 under stationary-phase conditions.
- 26Cruz-García, C.; Murray, A. E.; Klappenbach, J. A.; Stewart, V.; Tiedje, J. M. Respiratory Nitrate Ammonification by Shewanella oneidensis MR-1. J. Bacteriol. 2007, 189 (2), 656– 662, DOI: 10.1128/JB.01194-06Google Scholar26https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXpt1WqtQ%253D%253D&md5=c9540071da0ab68c7e2e26401e4a597eRespiratory nitrate ammonification by Shewanella oneidensis MR-1Cruz-Garcia, Claribel; Murray, Alison E.; Klappenbach, Joel A.; Stewart, Valley; Tiedje, James M.Journal of Bacteriology (2007), 189 (2), 656-662CODEN: JOBAAY; ISSN:0021-9193. (American Society for Microbiology)Anaerobic cultures of Shewanella oneidensis MR-1 grown with nitrate as the sole electron acceptor exhibited sequential redn. of nitrate to nitrite and then to ammonium. Little dinitrogen and nitrous oxide were detected, and no growth occurred on nitrous oxide. A mutant with the napA gene encoding periplasmic nitrate reductase deleted could not respire or assimilate nitrate and did not express nitrate reductase activity, confirming that the NapA enzyme is the sole nitrate reductase. Hence, S. oneidensis MR-1 conducts respiratory nitrate ammonification, also termed dissimilatory nitrate redn. to ammonium, but not respiratory denitrification.
tiejej@msu.edu.
- 27Han, H.-X.; Tian, L.-J.; Liu, D.-F.; Yu, H.-Q.; Sheng, G.-P.; Xiong, Y. Reversing Electron Transfer Chain for Light-Driven Hydrogen Production in Biotic–Abiotic Hybrid Systems. J. Am. Chem. Soc. 2022, 144, 6434, DOI: 10.1021/jacs.2c00934Google Scholar27https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XovVSiurs%253D&md5=b79956f07000ec63ee949c8b021fbf79Reversing electron transfer chain for light-driven hydrogen production in biotic-abiotic hybrid systemsHan, He-Xing; Tian, Li-Jiao; Liu, Dong-Feng; Yu, Han-Qing; Sheng, Guo-Ping; Xiong, YujieJournal of the American Chemical Society (2022), 144 (14), 6434-6441CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)The biotic-abiotic photosynthetic system integrating inorg. light absorbers with whole-cell biocatalysts innovates the way for sustainable solar-driven chem. transformation. Fundamentally, the electron transfer at the biotic-abiotic interface, which may induce biol. response to photoexcited electron stimuli, plays an essential role in solar energy conversion. Herein, we selected an electro-active bacterium Shewanella oneidensis MR-1 as a model, which constitutes a hybrid photosynthetic system with a self-assembled CdS semiconductor, to demonstrate unique biotic-abiotic interfacial behavior. The photoexcited electrons from CdS nanoparticles can reverse the extracellular electron transfer (EET) chain within S. oneidensis MR-1, realizing the activation of a bacterial catalytic network with light illumination. As compared with bare S. oneidensis MR-1, a significant upregulation of hydrogen yield (711-fold), ATP, and reducing equiv. (NADH/NAD+) was achieved in the S. oneidensis MR-1-CdS under visible light. This work sheds light on the fundamental mechanism and provides design guidelines for biotic-abiotic photosynthetic systems.
- 28Xiao, X.; Li, C.-X.; Peng, J.-R.; Fan, Y.-Y.; Li, W.-W. Dynamic Roles of Inner Membrane Electron-Transfer Hub of Shewanella oneidensis MR-1 in Response to Extracellular Reduction Kinetics. Chem. Eng. J. 2023, 451, 138717 DOI: 10.1016/j.cej.2022.138717Google Scholar28https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xit1emt7jE&md5=ce2eaf982902ecc549cb7a727f983f38Dynamic roles of inner membrane electron-transfer hub of Shewanella oneidensis MR-1 in response to extracellular reduction kineticsXiao, Xiang; Li, Chang-Xing; Peng, Jie-Ru; Fan, Yang-Yang; Li, Wen-WeiChemical Engineering Journal (Amsterdam, Netherlands) (2023), 451 (Part_2), 138717CODEN: CMEJAJ; ISSN:1385-8947. (Elsevier B.V.)The unique extracellular electron transfer (EET) network of exoelectrogens endow them with extraordinary extracellular respiration ability to facilitate environmental remediation and biogeochem. processes. Shewanella oneidensis MR-1 is an environmentally ubiquitous exoelectrogen possessing multiple EET pathways. While the inner membrane CymA protein is widely believed to serve as an essential electron transfer hub in all these pathways, here our exptl. evidences suggest another possibility: its EET role is highly dependent on extracellular redn. kinetics. Comparison of the bacterial EET and extracellular redn. performances in response to different species and concns. of extracellular electron acceptors shows that the fraction of electron efflux contributed by the CymA pathway is pos. correlated to the EET rate. This means some unknown EET pathways independent of CymA are activated under slow EET condition, likely as a strategy of self-adaptation to environmental changes by feedback regulating the electron transport pathways. Our findings provide a new perspective to facilitate better understanding of the dynamic bacteria-environment interactions, and may inspire the discovery of new EET proteins and the development of more environmentally-robust biotechnologies for environmental remediation applications.
- 29Schwalb, C.; Chapman, S. K.; Reid, G. A. The tetraheme Cytochrome CymA Is Required for Anaerobic Respiration with Dimethyl Sulfoxide and Nitrite in Shewanella oneidensis. Biochemistry 2003, 42 (31), 9491– 9497, DOI: 10.1021/bi034456fGoogle Scholar29https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXlsVGiu7o%253D&md5=f54aba4645eff55aec601947fc27cc6fThe Tetraheme Cytochrome CymA Is Required for Anaerobic Respiration with Dimethyl Sulfoxide and Nitrite in Shewanella oneidensisSchwalb, Carsten; Chapman, Stephen K.; Reid, Graeme A.Biochemistry (2003), 42 (31), 9491-9497CODEN: BICHAW; ISSN:0006-2960. (American Chemical Society)The tetraheme c-type cytochrome, CymA, from Shewanella oneidensis MR-1 has previously been shown to be required for respiration with Fe(III), nitrate, and fumarate. It is located in the cytoplasmic membrane where the bulk of the protein is exposed to the periplasm, enabling it to transfer electrons to a series of redox partners. The authors have expressed and purified a sol. deriv. of CymA (CymAsol) that lacks the N-terminal membrane anchor. The authors show here, by direct measurements of electron transfer between the purified proteins, that CymAsol efficiently reduces S. oneidensis fumarate reductase. This indicates that no further proteins are required for electron transfer between the quinone pool and fumarate if the authors assume direct redn. of CymA by quinols. By expressing CymAsol in a mutant lacking CymA, the authors have shown that this sol. form of the protein can complement the defect in fumarate respiration. The authors also demonstrate that CymA is essential for growth with DMSO and for redn. of nitrite, implicating CymA in at least five different electron transfer pathways in Shewanella.
- 30Logan, B. E.; Hamelers, B.; Rozendal, R.; Schröder, U.; Keller, J.; Freguia, S.; Aelterman, P.; Verstraete, W.; Rabaey, K. Microbial Fuel Cells: Methodology and Technology. Environ. Sci. Technol. 2006, 40 (17), 5181– 5192, DOI: 10.1021/es0605016Google Scholar30https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XmvVeisrs%253D&md5=136609c45b85681f70d4e0a0d5eab061Microbial Fuel Cells: Methodology and TechnologyLogan, Bruce E.; Hamelers, Bert; Rozendal, Rene; Schroeder, Uwe; Keller, Juerg; Freguia, Stefano; Aelterman, Peter; Verstraete, Willy; Rabaey, KorneelEnvironmental Science & Technology (2006), 40 (17), 5181-5192CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)A review of the different materials and methods used to construct a microbial fuel cell (MFC), techniques used to analyze system performance, with recommendations on what information to include in MFC studies and useful ways to present results. MFC research is an evolving field that lacks established terminol. and methods for the anal. of system performance. This makes it difficult for researchers to compare devices. The construction and anal. of MFCs requires knowledge of different scientific and engineering fields, ranging from microbiol. and electrochem. to materials and environmental engineering. Describing MFC systems therefore involves an understanding of these different scientific and engineering principles.
- 31Li, X.-M.; Ding, L.-J.; Zhu, D.; Zhu, Y.-G. Long-Term Fertilization Shapes the Putative Electrotrophic Microbial Community in Paddy Soils Revealed by Microbial Electrosynthesis Systems. Environ. Sci. Technol. 2021, 55 (5), 3430– 3441, DOI: 10.1021/acs.est.0c08022Google Scholar31https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXkt1Oqur4%253D&md5=e379089c6f4395af3d065186756dafe6Long-Term Fertilization Shapes the Putative Electrotrophic Microbial Community in Paddy Soils Revealed by Microbial Electrosynthesis SystemsLi, Xiao-Min; Ding, Long-Jun; Zhu, Dong; Zhu, Yong-GuanEnvironmental Science & Technology (2021), 55 (5), 3430-3441CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Electrotrophs play an important role in biogeochem. cycles, but the effects of long-term fertilization on electrotrophic communities in paddy soils remain unclear. Here, we explored the responses of electrotrophic communities in paddy soil-based microcosms to different long-term fertilization practices using microbial electrosynthesis systems (MESs), high-throughput quant. PCR, and 16s rRNA gene-based Illumina sequencing techniques. Compared to the case in the unfertilized soil (CK), applications of only manure (M); only chem. nitrogen, phosphorous, and potassium fertilizers (NPK); and M plus NPK (MNPK) clearly changed the electrotrophic bacterial community structure. The Streptomyces genus of the Actinobacteria phylum was the dominant electrotroph in the CK, M, and MNPK soils. The latter two soils also favored Truepera of Deinococcus-Thermus or Arenimonas and Thioalkalispira of Proteobacteria. Furthermore, Pseudomonas of Proteobacteria and Bacillus of Firmicutes were major electrotrophs in the NPK soil. These electrotrophs consumed biocathodic currents coupled with nitrate redn. and recovered 18-38% of electrons via dissimilatory nitrate redn. to ammonium (DNRA). The increased abundances of the nrfA gene for DNRA induced by elec. potential further supported that the electrotrophs enhanced DNRA for all soils. These expand our knowledge about the diversity of electrotrophs and their roles in N cycle in paddy soils and highlight the importance of fertilization in shaping electrotrophic communities. The 16S rRNA gene-based sequencing data have been deposited to the NCBI SRA under the accession nos. PRJNA600772, SAMN13831192 to SAMN13831215.
- 32Wu, Y.; Du, Q.; Wan, Y.; Zhao, Q.; Li, N.; Wang, X. Autotrophic Nitrate Reduction to Ammonium via Reverse Electron Transfer in Geobacter Dominated Biofilm. Biosens. Bioelectron. 2022, 215, 114578 DOI: 10.1016/j.bios.2022.114578Google Scholar32https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XitVWksb%252FN&md5=a6ebe0a4cf27ce20051e9c4a5ab78366Autotrophic nitrate reduction to ammonium via reverse electron transfer in Geobacter dominated biofilmWu, Yue; Du, Qing; Wan, Yuxuan; Zhao, Qian; Li, Nan; Wang, XinBiosensors & Bioelectronics (2022), 215 (), 114578CODEN: BBIOE4; ISSN:0956-5663. (Elsevier B.V.)Geobacter dominated electroactive biofilms (EABs) have been demonstrated to perform bidirectional extracellular electron transfer (EET) in bioelectrochem. systems, but it is largely unknown when nitrate is the electron acceptor at the cathode. If reverse EET occurs on biocathode, this EAB has to perform dissimilatory nitrate redn. to ammonia (DNRA) rather than denitrification according to genomes. Here, we have proven the feasibility of reverse bioelectron transfer in EAB, achieving a DNRA efficiency up to 93 ± 3% and high Faraday efficiency of 74 ± 1%. Const. current was found to be more effective than const. potential to maintain Geobacter on the cathode, which highly dets. this electrotrophic respiration. The prevalent DNRA at const. current surpassed denitrification, demonstrated by the reverse tendencies of DNRA (nrfA) and denitrification (nirS anirK) gene transcription. Metatranscriptomics further revealed the possible electron uptake mechanisms by which the outer membrane (OmcZ and OmcB) and periplasmic cytochromes (PpcB and PpcD) may be involved. These findings extend our understanding of the bidirectional electron transfer and advance the applications of EABs.
- 33Su, W.; Zhang, L.; Li, D.; Zhan, G.; Qian, J.; Tao, Y. dissimilatory Nitrate Reduction by Pseudomonas Alcaliphila with an Electrode as the Sole Electron Donor. Biotechnol. Bioeng. 2012, 109 (11), 2904– 2910, DOI: 10.1002/bit.24554Google Scholar33https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XnslOisbY%253D&md5=37fc545503048e1b83907ac43191e682Dissimilatory nitrate reduction by Pseudomonas alcaliphila with an electrode as the sole electron donorSu, Wentao; Zhang, Lixia; Li, Daping; Zhan, Guoqiang; Qian, Junwei; Tao, YongBiotechnology and Bioengineering (2012), 109 (11), 2904-2910CODEN: BIBIAU; ISSN:0006-3592. (John Wiley & Sons, Inc.)Denitrification and dissimilatory nitrate redn. to ammonium (DNRA) were considered two alternative pathways of dissimilatory nitrate redn. In this study, we firstly reported that both denitrification and DNRA occurred in Pseudomonas alcaliphila strain MBR with an electrode as the sole electron donor in a double chamber bio-electrochem. system (BES). The initial concn. of nitrate appeared as a factor detg. the type of nitrate redn. with electrode as the sole electron donor at the same potential (-500 mV). As the initial concn. of nitrate increased, the fraction of nitrate reduced through denitrification also increased. While nitrite (1.38 ± 0.04 mM) was used as electron acceptor instead of nitrate, the electrons recovery via DNRA and denitrification were 43.06 ± 1.02% and 50.51 ± 1.37%, resp. The electrochem. activities and surface topog. of the working electrode catalyzed by strain MBR were evaluated by cyclic voltammetry and SEM. The results suggested that cells of strain MBR were adhered to the electrode, playing the role of electron transfer media for nitrate and nitrite redn. Thus, for the first time, the results that DNRA and denitrification occurred simultaneously were confirmed by powering the strain with electricity. The study further expanded the range of metabolic reactions and had potential value for the recognization of dissimilatory nitrate redn. in various ecosystems. Biotechnol. Bioeng. © 2012 Wiley Periodicals, Inc.
- 34Liang, D.; Li, C.; He, W.; Li, Z.; Feng, Y. Response of Exoelectrogens Centered Consortium to Nitrate on Collaborative Metabolism, Microbial Community, and Spatial Structure. Chem. Eng. J. 2021, 426, 130975 DOI: 10.1016/j.cej.2021.130975Google ScholarThere is no corresponding record for this reference.
- 35Liang, D.; He, W.; Li, C.; Wang, F.; Crittenden, J. C.; Feng, Y. Remediation of Nitrate Contamination by Membrane Hydrogenotrophic Denitrifying Biofilm Integrated in Microbial Electrolysis Cell. Water Res. 2021, 188, 116498 DOI: 10.1016/j.watres.2020.116498Google Scholar35https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitV2lt7vL&md5=7aa6295cbab2851d9548e8d94f24b812Remediation of nitrate contamination by membrane hydrogenotrophic denitrifying biofilm integrated in microbial electrolysis cellLiang, Dandan; He, Weihua; Li, Chao; Wang, Fei; Crittenden, John C.; Feng, YujieWater Research (2021), 188 (), 116498CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)Complete biol. denitrification is usually restricted in electron donor lacking waters. Hydrogenotrophic denitrification attracts attention for its clean and cost-efficiency advantages. Therein, the hydrogen could be effectively generated by microbial electrolysis cells (MECs) from org. wastes. In this study, a gas diffusion membrane (GDM) integrated MEC (MMEC) was constructed and provided a novel non-polluting approach for nitrate contaminated water remediation, in which the hydrogen was recovered from substrate degrdn. in anode and diffused across GDM as electron donor for denitrification. The high overall nitrogen removal of 91 ± 0.1%-95 ± 1.9% and 90 ± 1.6%-94 ± 2.2% were resp. achieved in Ti-MMEC and SS-MMEC with titanium and stainless-steel mesh as cathode at all applied voltages (0.4-0.8 V). Decreasing applied voltage from 0.8 to 0.4 V significantly improved the electron utilization efficiency for denitrification from 26 ± 3.6% to 73 ±0.1% in Ti-MMEC. Integrating MEC with GDM greatly improved TN removal by 40% under applied voltage of 0.8 V. The hydrogenotrophic denitrifiers of Rhodocyclaceae, Paracoccus, and Dethiobacter, dominated in MMECs facilitating TN removal. Functional denitrification related genes including napAB, nirKS, norBC and nosZ predicted by PICRUSt2 based on 16S rRNA gene data demonstrated higher abundance in MMECs.
- 36Li, F.; Li, F.; Lin, Y.; Guo, L.; Zhang, L.; Li, R.; Tian, Q.; Wang, Y.; Wang, Y.; Zhang, X.; Liu, J.; Fan, C. Investigating the Performance and Mechanism of Nitrogen Gas Fixation and Conversion to Ammonia Based on biocathode bioelectrochemistry System. J. Chem. Technol. Biotechnol. 2022, 97 (8), 2163– 2170, DOI: 10.1002/jctb.7092Google ScholarThere is no corresponding record for this reference.
- 37Zhang, L.; Tian, C.; Wang, H.; Gu, W.; Zheng, D.; Cui, M.; Wang, X.; He, X.; Zhan, G.; Li, D. Improving Electroautotrophic Ammonium Production from Nitrogen Gas by Simultaneous Carbon Dioxide Fixation in a Dual–chamber Microbial Electrolysis Cell. bioelectrochemistry 2022, 144, 108044 DOI: 10.1016/j.bioelechem.2021.108044Google ScholarThere is no corresponding record for this reference.
- 38Chen, S.; Jing, X.; Yan, Y.; Huang, S.; Liu, X.; Chen, P.; Zhou, S. bioelectrochemical Fixation of Nitrogen to Extracellular Ammonium by Pseudomonas stutzeri. Appl. Environ. Microbiol. 2021, 87 (5), e01998– 20, DOI: 10.1128/AEM.01998-20Google ScholarThere is no corresponding record for this reference.
- 39Coursolle, D.; Gralnick, J. A. Modularity of the Mtr Respiratory Pathway of Shewanella oneidensis Strain MR-1. Mol. Microbiol. 2010, 77 (4), 995– 1008, DOI: 10.1111/j.1365-2958.2010.07266.xGoogle Scholar39https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtFaisrrF&md5=21c610081a0da9a367b67a807107b965Modularity of the Mtr respiratory pathway of Shewanella oneidensis strain MR-1Coursolle, Dan; Gralnick, Jeffrey A.Molecular Microbiology (2010), 77 (4), 995-1008CODEN: MOMIEE; ISSN:0950-382X. (Wiley-Blackwell)Four distinct pathways predicted to facilitate electron flow for respiration of externally located substrates are encoded in the genome of Shewanella oneidensis strain MR-1. Although the pathways share a suite of similar proteins, the activity of only two of these pathways has been described. Respiration of extracellular substrates requires a mechanism to facilitate electron transfer from the quinone pool in the cytoplasmic membrane to terminal reductase enzymes located on the outer leaflet of the outer membrane. The four pathways share MtrA paralogs, a periplasmic electron carrier cytochrome, and terminal reductases similar to MtrC for redn. of metals, flavins and electrodes or to DmsAB for redn. of DMSO. The promiscuity of respiratory electron transfer reactions catalyzed by these pathways has made studying strains lacking single proteins difficult. Here, the authors present a comprehensive anal. of MtrA and MtrC paralogs in S. oneidensis to define the roles of these proteins in respiration of insol. iron oxide, sol. iron citrate, flavins and DMSO. They present evidence that some periplasmic electron carrier components and terminal reductases in these pathways can provide partial compensation in the absence of the primary component, a phenomenon described as modularity, and discuss biochem. and evolutionary implications.
- 40Song, Y. E.; Mohamed, A.; Kim, C.; Kim, M.; Li, S.; Sundstrom, E.; Beyenal, H.; Kim, J. R. Biofilm Matrix and Artificial Mediator for Efficient Electron Transport in CO2Microbial Electrosynthesis. Chem. Eng. J. 2022, 427, 131885 DOI: 10.1016/j.cej.2021.131885Google ScholarThere is no corresponding record for this reference.
- 41Yu, C.; Qiao, S.; Zhou, J. Sulfide-Driven Nitrous Oxide Recovery during the Mixotrophic Denitrification Process. J. Environ. Sci. 2023, 125, 443– 452, DOI: 10.1016/j.jes.2021.12.003Google ScholarThere is no corresponding record for this reference.
- 42Firer-Sherwood, M.; Pulcu, G. S.; Elliott, S. J. Electrochemical Interrogations of the Mtr cytochromes from Shewanella: Opening a Potential Window. JBIC J. Biol. Inorg. Chem. 2008, 13 (6), 849– 854, DOI: 10.1007/s00775-008-0398-zGoogle Scholar42https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXovFOmsLw%253D&md5=0e1933c9ac286bc06176fb78dad98993Electrochemical interrogations of the Mtr cytochromes from Shewanella: opening a potential windowFirer-Sherwood, Mackenzie; Pulcu, Goekce Su; Elliott, Sean J.JBIC, Journal of Biological Inorganic Chemistry (2008), 13 (6), 849-854CODEN: JJBCFA; ISSN:0949-8257. (Springer GmbH)The multi-heme cytochromes from Shewanella oneidensis assocd. with the dissimilatory metal redn. (DMR) pathway have been investigated using the technique of protein film voltammetry (PFV). Using PFV, we have interrogated each of the multi-heme cytochromes (MtrA, STC, and solubilized versions of the membrane-bound proteins CymA, OmcA, and MtrC) under identical conditions for the first time. Each cytochrome reveals a broad envelope of voltammetric response, indicative of multiple redox cofactors that span a range of potential of approx. 300 mV. Our studies show that, when considered as an aggregate pathway, the multiple hemes of the DMR cytochromes provide a "window" of operating potential for electron transfer to occur from the cellular interior to the exterior spanning values of -250 to 0 mV (at circumneutral values of pH). Similarly, each cytochrome supports interfacial electron transfer at rates on the order of 200 s-1. These data are taken together to suggest a model of electron transport where a wide window of potential allows for charge transfer from the cellular interior to the exterior to support bioenergetics.
- 43Xiao, Y.; Zhang, E.; Zhang, J.; Dai, Y.; Yang, Z.; Christensen, H. E. M.; Ulstrup, J.; Zhao, F. Extracellular Polymeric Substances Are Transient Media for Microbial Extracellular Electron Transfer. Sci. Adv. 2017, 3 (7), e1700623 DOI: 10.1126/sciadv.1700623Google Scholar43https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXntVOlu78%253D&md5=4ff1a579f568ef80f632b757ffd2c384Extracellular polymeric substances are transient media for microbial extracellular electron transferXiao, Yong; Zhang, Enhua; Zhang, Jingdong; Dai, Youfen; Yang, Zhaohui; Christensen, Hans E. M.; Ulstrup, Jens; Zhao, FengScience Advances (2017), 3 (7), e1700623/1-e1700623/8CODEN: SACDAF; ISSN:2375-2548. (American Association for the Advancement of Science)Microorganisms exploit extracellular electron transfer (EET) in growth and information exchange with external environments or with other cells. Every microbial cell is surrounded by extracellular polymeric substances (EPS). Understanding the roles of three-dimensional (3D) EPS in EET is essential in microbiol. and microbial exploitation for mineral bio-respiration, pollutant conversion, and bioenergy prodn. We have addressed these challenges by comparing pure and EPS-depleted samples of three representative electrochem. active strains viz Gram-neg. Shewanella oneidensis MR-1, Gram-pos. Bacillus sp. WS-XY1, and yeast Pichia stipites using technol. from electrochem., spectroscopy, at. force microscopy, and microbiol. Voltammetry discloses redox signals from cytochromes and flavins in intact MR-1 cells, whereas stronger signals from cytochromes and addnl. signals from both flavins and cytochromes are found after EPS depletion. Flow cytometry and fluorescence microscopy substantiated by N-acetylglucosamine and electron transport system activity data showed less than 1.5% cell damage after EPS extn. The electrochem. differences between normal and EPS-depleted cells therefore originate from electrochem. species in cell walls and EPS. The 35 ± 15-nm MR-1 EPS layer is also electrochem. active itself, with cytochrome electron transfer rate consts. of 0.026 and 0.056 s-1 for intact MR-1 and EPS-depleted cells, resp. This surprisingly small rate difference suggests thatmol. redox species at the core of EPS assist EET. The combination of all the data with electron transfer anal. suggests that electron "hopping" is the most likely mol. mechanism for electrochem. electron transfer through EPS.
- 44Marsili, E.; Baron, D. B.; Shikhare, I. D.; Coursolle, D.; Gralnick, J. A.; Bond, D. R. Shewanella Secretes Flavins That Mediate Extracellular Electron Transfer. Proc. Natl. Acad. Sci. U. S. A. 2008, 105 (10), 3968– 3973, DOI: 10.1073/pnas.0710525105Google Scholar44https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXjs1Oms7g%253D&md5=0685a57798612487118ba67d026310c5Shewanella secretes flavins that mediate extracellular electron transferMarsili, Enrico; Baron, Daniel B.; Shikhare, Indraneel D.; Coursolle, Dan; Gralnick, Jeffrey A.; Bond, Daniel R.Proceedings of the National Academy of Sciences of the United States of America (2008), 105 (10), 3968-3973CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Bacteria able to transfer electrons to metals are key agents in biogeochem. metal cycling, subsurface bioremediation, and corrosion processes. More recently, these bacteria have gained attention as the transfer of electrons from the cell surface to conductive materials can be used in multiple applications. In this work, we adapted electrochem. techniques to probe intact biofilms of Shewanella oneidensis MR-1 and Shewanella sp. MR-4 grown by using a poised electrode as an electron acceptor. This approach detected redox-active mols. within biofilms, which were involved in electron transfer to the electrode. A combination of methods identified a mixt. of riboflavin and riboflavin-5'-phosphate in supernatants from biofilm reactors, with riboflavin representing the dominant component during sustained incubations (>72 h). Removal of riboflavin from biofilms reduced the rate of electron transfer to electrodes by >70%, consistent with a role as a sol. redox shuttle carrying electrons from the cell surface to external acceptors. Differential pulse voltammetry and cyclic voltammetry revealed a layer of flavins adsorbed to electrodes, even after sol. components were removed, esp. in older biofilms. Riboflavin adsorbed quickly to other surfaces of geochem. interest, such as Fe(III) and Mn(IV) oxy(hydr)oxides. This in situ demonstration of flavin prodn., and sequestration at surfaces, requires the paradigm of sol. redox shuttles in geochem. to be adjusted to include binding and modification of surfaces. Moreover, the known ability of isoalloxazine rings to act as metal chelators, along with their electron shuttling capacity, suggests that extracellular respiration of minerals by Shewanella is more complex than originally conceived.
- 45Okamoto, A.; Hashimoto, K.; Nealson, K. H.; Nakamura, R. Rate Enhancement of Bacterial Extracellular Electron Transport Involves Bound flavin Semiquinones. Proc. Natl. Acad. Sci. U. S. A. 2013, 110 (19), 7856– 7861, DOI: 10.1073/pnas.1220823110Google Scholar45https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXptFGrtb8%253D&md5=a666542718effb789080d7bb0427c0b6Rate enhancement of bacterial extracellular electron transport involves bound flavin semiquinonesOkamoto, Akihiro; Hashimoto, Kazuhito; Nealson, Kenneth H.; Nakamura, RyuheiProceedings of the National Academy of Sciences of the United States of America (2013), 110 (19), 7856-7861, S7856/1-S7856/6CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Extracellular redox-active compds., flavins and other quinones, have been hypothesized to play a major role in the delivery of electrons from cellular metabolic systems to extracellular insol. substrates by a diffusion-based shuttling two-electron-transfer mechanism. Here, the authors show that flavin mols. secreted by Shewanella oneidensis MR-1 enhance the ability of its outer membrane c-type cytochromes (OM c-Cyts) to transport electrons as redox cofactors, but not free-form flavins. Whole-cell differential pulse voltammetry revealed that the redox potential of flavin was reversibly shifted more than 100 mV in a pos. direction, in good agreement with increasing microbial current generation. Importantly, this flavin/OM c-Cyts interaction was found to facilitate a one-electron redox reaction via a semiquinone, resulting in a 103- to 105-fold faster reaction rate than that of free flavin. These results are not consistent with previously proposed redox-shuttling mechanisms but suggest that the flavin/OM c-Cyts interaction regulates the extent of extracellular electron transport coupled with intracellular metabolic activity.
- 46Carmona-Martinez, A. A.; Harnisch, F.; Fitzgerald, L. A.; Biffinger, J. C.; Ringeisen, B. R.; Schröder, U. Cyclic Voltammetric Analysis of the Electron Transfer of Shewanella oneidensis MR-1 and Nanofilament and Cytochrome Knock-out Mutants. bioelectrochemistry 2011, 81 (2), 74– 80, DOI: 10.1016/j.bioelechem.2011.02.006Google Scholar46https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXmsVynt7c%253D&md5=b071994b1d58105ad8ab27e948ac600eCyclic voltammetric analysis of the electron transfer of Shewanella oneidensis MR-1 and nanofilament and cytochrome knock-out mutantsCarmona-Martinez, Alessandro A.; Harnisch, Falk; Fitzgerald, Lisa A.; Biffinger, Justin C.; Ringeisen, Bradley R.; Schroeder, UweBioelectrochemistry (2011), 81 (2), 74-80CODEN: BIOEFK; ISSN:1567-5394. (Elsevier B.V.)Shewanella is frequently used as a model microorganism for microbial bioelectrochem. systems. In this study, we used cyclic voltammetry (CV) to investigate extracellular electron transfer mechanisms from S. oneidensis MR-1 (WT) and five deletion mutants: membrane bound cytochrome (ΔmtrC/ΔomcA), transmembrane pili (ΔpilM-Q, ΔmshH-Q, and ΔpilM-Q/ΔmshH-Q) and flagella (Δflg). We demonstrate that the formal potentials of mediated and direct electron transfer sites of the derived biofilms can be gained from CVs of the resp. biofilms recorded at bioelectrocatlytic (i.e. turnover) and lactate depleted (i.e. non-turnover) conditions. As the biofilms possess only a limited bioelectrocatalytic activity, an advanced data processing procedure, using the open-source software SOAS, was applied. The obtained results indicate that S. oneidensis mutants used in this study are able to bypass hindered direct electron transfer by alternative redox proteins as well as self-mediated pathways.
- 47Wang, S.; Zhang, J.; Gharbi, O.; Vivier, V.; Gao, M.; Orazem, M. E. Electrochemical Impedance Spectroscopy. Nat. Rev. Methods Primer 2021, 1 (1), 1– 21, DOI: 10.1038/s43586-021-00039-wGoogle ScholarThere is no corresponding record for this reference.
- 48Menzinger, M.; Wolfgang, R. The Meaning and Use of the Arrhenius Activation Energy. Angew. Chem., Int. Ed. Engl. 1969, 8 (6), 438– 444, DOI: 10.1002/anie.196904381Google Scholar48https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaF1MXksVaks7o%253D&md5=2369482a85bbf9d9a85f442dc1700e4bMeaning and use of the Arrhenius activation energyMenzinger, Michael A.; Wolfgang, RichardAngewandte Chemie, International Edition in English (1969), 8 (6), 438-44CODEN: ACIEAY; ISSN:0570-0833.The nature of the Arrhenius activation energy and frequency factor is reexamd. in terms of data now available on the microscopic aspects of collisional reactions. The conceptual meaning of the activation energy is discussed, and the temp. dependence of this quantity and its relation to the threshold energy are developed for a no. of representative forms of the energy dependence of the reaction cross section. The uses and limitations of the activation energy as a means of evaluating thresholds, excitation functions, and the presence of tunneling processes are discussed.
- 49Angulo, A.; van der Linde, P.; Gardeniers, H.; Modestino, M.; Fernández Rivas, D. Influence of Bubbles on the Energy Conversion Efficiency of Electrochemical Reactors. Joule 2020, 4 (3), 555– 579, DOI: 10.1016/j.joule.2020.01.005Google Scholar49https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXlvVOmsLc%253D&md5=6c586c28ba85d5d4d737850510270532Influence of bubbles on the energy conversion efficiency of electrochemical reactorsAngulo, Andrea; van der Linde, Peter; Gardeniers, Han; Modestino, Miguel; Fernandez Rivas, DavidJoule (2020), 4 (3), 555-579CODEN: JOULBR; ISSN:2542-4351. (Cell Press)A review. Bubbles are known to influence energy and mass transfer in gas-evolving electrodes. However, we lack a detailed understanding on the intricate dependencies between bubble evolution processes and electrochem. phenomena. This review discusses our current knowledge on the effects of bubbles on electrochem. systems with the aim to identify opportunities and motivate future research in this area. We first provide a base background on the physics of bubble evolution as it relates to electrochem. processes. Then we outline how bubbles affect energy efficiency of electrode processes, detailing the bubble-induced impacts on activation, ohmic, and concn. overpotentials. Lastly, we describe different strategies to mitigate losses and how to exploit bubbles to enhance electrochem. reactions.
- 50Nevin, K. P.; Hensley, S. A.; Franks, A. E.; Summers, Z. M.; Ou, J.; Woodard, T. L.; Snoeyenbos-West, O. L.; Lovley, D. R. Electrosynthesis of Organic Compounds from Carbon Dioxide Is Catalyzed by a Diversity of Acetogenic Microorganisms. Appl. Environ. Microbiol. 2011, 77 (9), 2882– 2886, DOI: 10.1128/AEM.02642-10Google Scholar50https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtVeju7bF&md5=4293c1828d5f7e8dc43a9165ae02f247Electrosynthesis of organic compounds from carbon dioxide is catalyzed by a diversity of acetogenic microorganismsNevin, Kelly P.; Hensley, Sarah A.; Franks, Ashley E.; Summers, Zarath M.; Ou, Jianhong; Woodard, Trevor L.; Snoeyenbos-West, Oona L.; Lovley, Derek R.Applied and Environmental Microbiology (2011), 77 (9), 2882-2886CODEN: AEMIDF; ISSN:0099-2240. (American Society for Microbiology)Microbial electrosynthesis, a process in which microorganisms use electrons derived from electrodes to reduce carbon dioxide to multicarbon, extracellular org. compds., is a potential strategy for capturing elec. energy in carbon-carbon bonds of readily stored and easily distributed products, such as transportation fuels. To date, only one organism, the acetogen Sporomusa ovata, has been shown to be capable of electrosynthesis. The purpose of this study was to det. if a wider range of microorganisms is capable of this process. Several other acetogenic bacteria, including two other Sporomusa species, Clostridium ljungdahlii, Clostridium aceticum, and Moorella thermoacetica, consumed current with the prodn. of org. acids. In general acetate was the primary product, but 2-oxobutyrate and formate also were formed, with 2-oxobutyrate being the predominant identified product of electrosynthesis by C. aceticum. S. sphaeroides, C. ljungdahlii, and M. thermoacetica had high (>80%) efficiencies of electrons consumed and recovered in identified products. The acetogen Acetobacterium woodii was unable to consume current. These results expand the known range of microorganisms capable of electrosynthesis, providing multiple options for the further optimization of this process.
- 51Liu, X.; Huang, L.; Rensing, C.; Ye, J.; Nealson, K. H.; Zhou, S. Syntrophic Interspecies Electron Transfer Drives Carbon Fixation and Growth by Rhodopseudomonas Palustris under Dark, Anoxic Conditions. Sci. Adv. 2021, 7 (27), eabh1852 DOI: 10.1126/sciadv.abh1852Google ScholarThere is no corresponding record for this reference.
- 52Yang, G.; Huang, L.; You, L.; Zhuang, L.; Zhou, S. Electrochemical and Spectroscopic Insights into the Mechanisms of Bidirectional Microbe-Electrode Electron Transfer in Geobacter Soli Biofilms. Electrochem. Commun. 2017, 77, 93– 97, DOI: 10.1016/j.elecom.2017.03.004Google Scholar52https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXktVKlsLs%253D&md5=2ae0c667d9282871d734d584cb865b1bElectrochemical and spectroscopic insights into the mechanisms of bidirectional microbe-electrode electron transfer in Geobacter soli biofilmsYang, Guiqin; Huang, Lingyan; You, Lexing; Zhuang, Li; Zhou, ShunguiElectrochemistry Communications (2017), 77 (), 93-97CODEN: ECCMF9; ISSN:1388-2481. (Elsevier B.V.)Few electroactive bacteria have shown the capacity of exchanging electrons with electrode in both directions, and the mechanisms of such bidirectional electron transfer remain uncertain hitherto. In this study, we demonstrate that Geobacter soli biofilms could directly donate electrons to and accept electrons from graphite electrode. Under anodic conditions, G. soli oxidizes acetate to generate current, and under cathodic conditions, nitrate is reduced by a truncated denitrification pathway with nitrous oxide as end product. Cyclic voltammetry, differential pulse voltammetry and electrochem. in situ FTIR spectra demonstrate that distinct external membrane redox systems exist in the anode and cathode biofilms, which supports the conclusion that G. soli uses different electron transfer conduits for bidirectional electron transfer. These results expand the horizon of bidirectional electron transfer mechanisms, meanwhile this study represents a first report that Geobacter species might utilize electrode as electron donor for incomplete denitrification.
- 53Yu, Q.; Mao, H.; Yang, B.; Zhu, Y.; Sun, C.; Zhao, Z.; Li, Y.; Zhang, Y. Electro-Polarization of Protein-like Substances Accelerates Trans-Cell-Wall Electron Transfer in Microbial Extracellular Respiration. iScience 2023, 26 (2), 106065 DOI: 10.1016/j.isci.2023.106065Google ScholarThere is no corresponding record for this reference.
- 54Yu, Q.; Zhang, Y. Fouling-Resistant Biofilter of an Anaerobic Electrochemical Membrane Reactor. Nat. Commun. 2019, 10 (1), 4860, DOI: 10.1038/s41467-019-12838-7Google ScholarThere is no corresponding record for this reference.
- 55Dubois, V.; Umari, P.; Pasquarello, A. Dielectric Susceptibility of Dipolar Molecular Liquids by Ab Initio Molecular Dynamics: Application to Liquid HCl. Chem. Phys. Lett. 2004, 390 (1), 193– 198, DOI: 10.1016/j.cplett.2004.04.021Google ScholarThere is no corresponding record for this reference.
- 56Chen, L.; Li, X.; Xie, Y.; Liu, N.; Qin, X.; Chen, X.; Bu, Y. Modulation of Proton-Coupled Electron Transfer Reactions in Lysine-Containing Alpha-Helixes: Alpha-Helixes Promoting Long-Range Electron Transfer. Phys. Chem. Chem. Phys. 2022, 24 (23), 14592– 14602, DOI: 10.1039/D2CP00666AGoogle ScholarThere is no corresponding record for this reference.
- 57Lauz, M.; Eckhardt, S.; Fromm, K. M.; Giese, B. The Influence of Dipole Moments on the Mechanism of Electron Transfer through Helical Peptides.. Phys. Chem. Chem. Phys. 2012, 14 (40), 13785– 13788, DOI: 10.1039/c2cp41159hGoogle ScholarThere is no corresponding record for this reference.
- 58Sawicka, A.; Skurski, P.; Hudgins, R. R.; Simons, J. Model Calculations Relevant to Disulfide Bond Cleavage via Electron Capture Influenced by Positively Charged Groups. J. Phys. Chem. B 2003, 107 (48), 13505– 13511, DOI: 10.1021/jp035675dGoogle Scholar58https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXovVClurw%253D&md5=c1000f8c129f9bcd0cd8881c33bd73faModel Calculations Relevant to Disulfide Bond Cleavage via Electron Capture Influenced by Positively Charged GroupsSawicka, Agnieszka; Skurski, Piotr; Hudgins, Robert R.; Simons, JackJournal of Physical Chemistry B (2003), 107 (48), 13505-13511CODEN: JPCBFK; ISSN:1520-6106. (American Chemical Society)Ab initio electronic structure calcns. are used to explore the effect of nonneighboring pos. charged groups on the ability of low-energy (<1 eV) electrons to directly attach to S-S σ bonds in disulfides to effect bond cleavage. It is shown that, although direct vertical attachment to the σ* orbital of an S-S σ bond is endothermic, the stabilizing Coulomb potential produced in the region of the S-S bond by one or more distant pos. groups can render the S-S σ* anion state electronically stable. This stabilization, in turn, can make near vertical electron attachment exothermic. The focus of these model studies is to elucidate a proposed mechanism for bond rupture that may, in addn. to other mechanisms, be operative in electron capture dissocn. (ECD) expts. The importance of these findings lies in the fact that a more complete understanding of how ECD takes place will allow workers to better interpret ECD fragmentation patterns obsd. in mass spectrometric studies of proteins and polypeptides.
- 59Okamoto, A.; Tokunou, Y.; Kalathil, S.; Hashimoto, K. Proton Transport in the Outer-Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron Transport. Angew. Chem., Int. Ed. 2017, 56 (31), 9082– 9086, DOI: 10.1002/anie.201704241Google Scholar59https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtV2gs7%252FJ&md5=4bbeb45d3d6b6037f4af828787f67177Proton Transport in the Outer-Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron TransportOkamoto, Akihiro; Tokunou, Yoshihide; Kalathil, Shafeer; Hashimoto, KazuhitoAngewandte Chemie, International Edition (2017), 56 (31), 9082-9086CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)The microbial transfer of electrons to extracellularly located solid compds., termed extracellular electron transport (EET), is crit. for microbial electrode catalysis. Although the components of the EET pathway in the outer membrane (OM) have been identified, the role of electron/cation coupling in EET kinetics is poorly understood. We studied the dynamics of proton transport assocd. with EET in an OM flavocytochrome complex in Shewanella oneidensis MR-1. Using a whole-cell electrochem. assay, a significant kinetic isotope effect (KIE) was obsd. following the addn. of deuterated water (D2O). The removal of a flavin cofactor or key components of the OM flavocytochrome complex significantly increased the KIE in the presence of D2O to values that were significantly larger than those reported for proton channels and ATP synthase, thus indicating that proton transport by OM flavocytochrome complexes limits the rate of EET.
- 60Kumar, A.; Hsu, L. H. H.; Kavanagh, P.; Barrière, F.; Lens, P. N. L.; Lapinsonnière, L.; Lienhard V, J. H.; Schröder, U.; Jiang, X.; Leech, D. The Ins and Outs of Microorganism–Electrode Electron Transfer Reactions. Nat. Rev. Chem. 2017, 1 (3), 1– 13, DOI: 10.1038/s41570-017-0024Google ScholarThere is no corresponding record for this reference.
- 61Ren, Y.; Yu, C.; Tan, X.; Huang, H.; Wei, Q.; Qiu, J. Strategies to Suppress Hydrogen Evolution for Highly Selective Electrocatalytic Nitrogen Reduction: Challenges and Perspectives. Energy Environ. Sci. 2021, 14 (3), 1176– 1193, DOI: 10.1039/D0EE03596CGoogle Scholar61https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhsVGnt7Y%253D&md5=1883f9ec644f0a417a4e9a9f1a0ca591Strategies to suppress hydrogen evolution for highly selective electrocatalytic nitrogen reduction: challenges and perspectivesRen, Yongwen; Yu, Chang; Tan, Xinyi; Huang, Hongling; Wei, Qianbing; Qiu, JieshanEnergy & Environmental Science (2021), 14 (3), 1176-1193CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)A review. Ammonia, as a significant chem. for fertilizer prodn. and also a promising energy carrier, is mainly produced through the traditional energy-intensive Haber-Bosch process. Recently, the electrocatalytic N2 redn. reaction (NRR) for ammonia synthesis has received tremendous attention with the merits of energy saving and environmental friendliness. To date, the development of the NRR process is primarily hindered by the competing hydrogen evolution reaction (HER), whereas the corresponding strategies for inhibiting this undesired side reaction to achieve high NRR selectivity are still quite limited. Furthermore, for such a complex reaction involving three gas-liq.-solid phases and proton/electron transfer, it is also rather meaningful to decouple and summarize the current strategies for suppressing H2 evolution in terms of NRR mechanisms, kinetics, thermodn., and electrocatalyst design in detail. Herein, on the basis of the NRR mechanisms, we systematically summarize the recent strategies to inhibit the HER for a highly selective electrocatalytic NRR, focusing on limiting the proton- and electron-transfer kinetics, shifting the chem. equil., and designing the electrocatalysts. Addnl., insights into boosting the NRR selectivity and efficiency for practical applications are also presented in detail with regard to the detn. of ammonia, the activation of the N2 mol., the regulation of the gas-liq.-solid three-phase interface, the coupled NRR with value-added oxidn. reactions, and the development of flow cell reactors.
- 62van der Ham, C. J. M.; Koper, M. T. M.; Hetterscheid, D. G. H. Challenges in Reduction of Dinitrogen by Proton and Electron Transfer. Chem. Soc. Rev. 2014, 43 (15), 5183– 5191, DOI: 10.1039/C4CS00085DGoogle Scholar62https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFWhsL3E&md5=7a634f6a6cdb86ca035e350c604b4007Challenges in reduction of dinitrogen by proton and electron transfervan der Ham, Cornelis J. M.; Koper, Marc T. M.; Hetterscheid, Dennis G. H.Chemical Society Reviews (2014), 43 (15), 5183-5191CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)A review. Ammonia is an important nutrient for the growth of plants. In industry, ammonia is produced by the energy expensive Haber-Bosch process where dihydrogen and dinitrogen form ammonia at a very high pressure and temp. In principle one could also reduce dinitrogen upon addn. of protons and electrons similar to the mechanism of ammonia prodn. by nitrogenases. Recently, major breakthroughs have taken place in our understanding of biol. fixation of dinitrogen, of mol. model systems that can reduce dinitrogen, and in the electrochem. redn. of dinitrogen at heterogeneous surfaces. Yet for efficient redn. of dinitrogen with protons and electrons major hurdles still have to be overcome. The authors give an overview of the different catalytic systems, highlight the recent breakthroughs, pinpoint common grounds and discuss the bottlenecks and challenges in catalytic redn. of dinitrogen.
- 63Ram, M.; Child, M.; Aghahosseini, A.; Bogdanov, D.; Lohrmann, A.; Breyer, C. A Comparative Analysis of Electricity Generation Costs from Renewable, Fossil Fuel and Nuclear Sources in G20 Countries for the Period 2015–2030. J. Clean. Prod. 2018, 199, 687– 704, DOI: 10.1016/j.jclepro.2018.07.159Google ScholarThere is no corresponding record for this reference.
- 64De Luna, P.; Hahn, C.; Higgins, D.; Jaffer, S. A.; Jaramillo, T. F.; Sargent, E. H. What Would It Take for Renewably Powered Electrosynthesis to Displace Petrochemical Processes?. Science 2019, 364 (6438), eaav3506 DOI: 10.1126/science.aav3506Google ScholarThere is no corresponding record for this reference.
- 65Sakimoto, K. K.; Wong, A. B.; Yang, P. Self-Photosensitization of Nonphotosynthetic Bacteria for Solar-to-Chemical Production. Science 2016, 351 (6268), 74– 77, DOI: 10.1126/science.aad3317Google Scholar65https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitV2nsbnI&md5=40593834d3255adc14e8c439838b1acbSelf-photosensitization of nonphotosynthetic bacteria for solar-to-chemical productionSakimoto, Kelsey K.; Wong, Andrew Barnabas; Yang, PeidongScience (Washington, DC, United States) (2016), 351 (6268), 74-77CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Improving natural photosynthesis can enable the sustainable prodn. of chems. However, neither purely artificial nor purely biol. approaches seem poised to realize the potential of solar-to-chem. synthesis. We developed a hybrid approach, whereby we combined the highly efficient light harvesting of inorg. semiconductors with the high specificity, low cost, and self-replication and -repair of biocatalysts. We induced the self-photosensitization of a nonphotosynthetic bacterium, Moorella thermoacetica, with cadmium sulfide nanoparticles, enabling the photosynthesis of acetic acid from carbon dioxide. Biol. pptd. cadmium sulfide nanoparticles served as the light harvester to sustain cellular metab. This self-augmented biol. system selectively produced acetic acid continuously over several days of light-dark cycles at relatively high quantum yields, demonstrating a self-replicating route toward solar-to-chem. carbon dioxide redn.
- 66Deng, X.; Dohmae, N.; Kaksonen, A. H.; Okamoto, A. Biogenic Iron Sulfide Nanoparticles to Enable Extracellular Electron Uptake in Sulfate-Reducing Bacteria. Angew. Chem. 2020, 132 (15), 6051– 6055, DOI: 10.1002/ange.201915196Google ScholarThere is no corresponding record for this reference.
Cited By
Click to copy section linkSection link copied!
This article has not yet been cited by other publications.
Article Views
1427
Altmetric
-
Citations
-
Learn about these metrics
Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.
Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.
The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.
Recommended Articles
Tandem Acidic CO2 Electrolysis Coupled with Syngas Fermentation: A Two-Stage Process for Producing Medium-Chain Fatty Acids
Using Network Analysis and Predictive Functional Analysis to Explore the Fluorotelomer Biotransformation Potential of Soil Microbial Communities
Regulating the Selectivity of Nitrate Photoreduction for Purification or Ammonia Production by Cooperating Oxidative Half-Reactions
Microbial Sources and Sinks of Nitrous Oxide during Organic Waste Composting
Microbially Induced Soil Colloidal Phosphorus Mobilization Under Anoxic Conditions
Abstract
Figure 1
Figure 1. Characteristics of the S. oneidensis@FeS system.
Figure 2
Figure 2. Nitrate reduction performances in S. oneidensis and S. oneidensis@FeS systems.
Figure 3
Figure 3. Nitrate reduction was by different mutants. (A) NO3–-N, (B) NO2–-N, and (C) NH4+-N concentrations. (D) Yield assessment. Each experiment was performed in triplicate, and error bars indicate the standard deviation.
Figure 4
Figure 4. Cathodic electron consumption in MES systems. Current density and coulomb in (A, B) S. oneidensis and (C, D) S. oneidensis@FeS systems. (E) Cathode efficiency and (F) a comparison of achievements.
Figure 5
Figure 5. Cathodic electron consumption by different mutants. (A) Current density, (B) Coulomb. (C) Cathode efficiency.
Figure 6
Figure 6. Electrochemical analysis in MES systems. Cyclic voltammetry curves, capacitance, Nyquist plots of electrochemical impedance spectroscopy, and the values of the Rs and Rct in (A–D) S. oneidensis and (E–H) S. oneidensis@FeS systems.
Figure 7
Figure 7. Electrochemical in-situ Fourier transform infrared spectra in (A) S. oneidensis and (B) S. oneidensis@FeS systems.
Figure 8
Figure 8. Schematic illustration of the mechanism. OmcA and MtrC, extracellular iron oxide respiratory system surface decaheme cytochrome c component; MtrB, extracellular iron oxide respiratory system outer membrane component; MtrA, extracellular iron oxide respiratory system periplasmic decaheme cytochrome c component; CymA, membrane anchored tetraheme c; MQ, menaquinone; MQH2, reduced form of menaquinone; NapB, periplasmic nitrate reductase cytochrome c subunit; NapA, periplasmic nitrate reductase molybdopterin-binding subunit; NrfA, ammonia-forming nitrite reductase.
References
This article references 66 other publications.
- 1Hollevoet, L.; Jardali, F.; Gorbanev, Y.; Creel, J.; Bogaerts, A.; Martens, J. A. Towards Green Ammonia Synthesis through Plasma-Driven Nitrogen Oxidation and Catalytic Reduction. Angew. Chem. 2020, 132 (52), 24033– 24037, DOI: 10.1002/ange.202011676There is no corresponding record for this reference.
- 2Jabarivelisdeh, B.; Jin, E.; Christopher, P.; Masanet, E. Model-Based Analysis of Ammonia Production Processes for Quantifying Energy Use, Emissions, and Reduction Potentials. ACS Sustain. Chem. Eng. 2022, 10 (49), 16280– 16289, DOI: 10.1021/acssuschemeng.2c04976There is no corresponding record for this reference.
- 3Soloveichik, G. Electrochemical Synthesis of Ammonia as a Potential Alternative to the Haber–Bosch Process. Nat. Catal. 2019, 2 (5), 377– 380, DOI: 10.1038/s41929-019-0280-03https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXpvVyqs7g%253D&md5=c06dc4f19fadfe8b694d2cb938c0cb1fElectrochemical synthesis of ammonia as a potential alternative to the Haber-Bosch processSoloveichik, GrigoriiNature Catalysis (2019), 2 (5), 377-380CODEN: NCAACP; ISSN:2520-1158. (Nature Research)The preeminent Haber-Bosch process has been feeding humankind for more than one hundred years. Are electrochem. pathways for ammonia synthesis able to compete with it in the future. Electrocatalysts, electrolytes and novel cell design may be key.
- 4Nayak-Luke, R. M.; Bañares-Alcántara, R. Techno-Economic Viability of Islanded Green Ammonia as a Carbon-Free Energy Vector and as a Substitute for Conventional Production. Energy Environ. Sci. 2020, 13 (9), 2957– 2966, DOI: 10.1039/D0EE01707H4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtlKku7rI&md5=77d56b4b05ee524beb3f85e763278ff7Techno-economic viability of islanded green ammonia as a carbon-free energy vector and as a substitute for conventional productionNayak-Luke, Richard Michael; Banares-Alcantara, ReneEnergy & Environmental Science (2020), 13 (9), 2957-2966CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)Decarbonising ammonia prodn. is an environmental imperative given that it independently accounts for 1.8% of global carbon dioxide emissions and supports the feeding of over 48% of the global population. The recent decline of prodn. costs and its potential as an energy vector warrant investigation of whether green ammonia prodn. is com. competitive. Considering 534 locations in 70 countries and designing and operating the islanded prodn. process to minimise the levelised cost of ammonia (LCOA) at each, we show the range of achievable LCOA, the cost of process flexibility, the components of LCOA, and therein the scope of LCOA redn. achievable at present and in 2030. These results are benchmarked against ammonia spot prices, cost per GJ of refined fuels and the LCOE of alternative energy storage methods. Currently a LCOA of $473 t-1 is achievable, at the best locations the required process flexibility increases the achievable LCOA by 56%; the electrolyzer CAPEX and operation are the most significant costs. By 2030, $310 t-1 is predicted to be achievable with multiple locations below $350 t-1. At $25.4 GJ-1 currently and $16.6 GJ-1 by 2030 prior combustion, this compares favorably against other refined fuels such as kerosene ($8.7-18.3 GJ-1) that do not have the benefit of being carbon-free.
- 5Bennaamane, S.; Rialland, B.; Khrouz, L.; Fustier-Boutignon, M.; Bucher, C.; Clot, E.; Mézailles, N. Ammonia Synthesis at Room Temperature and Atmospheric Pressure from N2: A Boron-Radical Approach. Angew. Chem. 2023, 135 (3), e202209102 DOI: 10.1002/ange.202209102There is no corresponding record for this reference.
- 6He, W.; Zhang, J.; Dieckhöfer, S.; Varhade, S.; Brix, A. C.; Lielpetere, A.; Seisel, S.; Junqueira, J. R. C.; Schuhmann, W. Splicing the Active Phases of Copper/Cobalt-Based Catalysts Achieves High-Rate Tandem Electroreduction of Nitrate to Ammonia. Nat. Commun. 2022, 13 (1), 1129, DOI: 10.1038/s41467-022-28728-46https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xls1Onsrs%253D&md5=c8773c74f69432802d06addeee800c4fSplicing the active phases of copper/cobalt-based catalysts achieves high-rate tandem electroreduction of nitrate to ammoniaHe, Wenhui; Zhang, Jian; Dieckhoefer, Stefan; Varhade, Swapnil; Brix, Ann Cathrin; Lielpetere, Anna; Seisel, Sabine; Junqueira, Joao R. C.; Schuhmann, WolfgangNature Communications (2022), 13 (1), 1129CODEN: NCAOBW; ISSN:2041-1723. (Nature Portfolio)Electrocatalytic recycling of waste nitrate (NO3-) to valuable ammonia (NH3) at ambient conditions is a green and appealing alternative to the Haber-Bosch process. However, the reaction requires multi-step electron and proton transfer, making it a grand challenge to drive high-rate NH3 synthesis in an energy-efficient way. Herein, we present a design concept of tandem catalysts, which involves coupling intermediate phases of different transition metals, existing at low applied overpotentials, as cooperative active sites that enable cascade NO3--to-NH3 conversion, in turn avoiding the generally encountered scaling relations. We implement the concept by electrochem. transformation of Cu-Co binary sulfides into potential-dependent core-shell Cu/CuOx and Co/CoO phases. Electrochem. evaluation, kinetic studies, and in-situ Raman spectra reveal that the inner Cu/CuOx phases preferentially catalyze NO3- redn. to NO2-, which is rapidly reduced to NH3 at the nearby Co/CoO shell. This unique tandem catalyst system leads to a NO3--to-NH3 Faradaic efficiency of 93.3 ± 2.1% in a wide range of NO3- concns. at pH 13, a high NH3 yield rate of 1.17 mmol cm-2 h-1 in 0.1 M NO3- at -0.175 V vs. RHE, and a half-cell energy efficiency of ∼36%, surpassing most previous reports.
- 7Teng, J.; Deng, Y.; Zhou, X.; Yang, W.; Huang, Z.; Zhang, H.; Zhang, M.; Lin, H. A Critical Review on Thermodynamic Mechanisms of Membrane Fouling in Membrane-Based Water Treatment Process. Front. Environ. Sci. Eng. 2023, 17 (10), 129, DOI: 10.1007/s11783-023-1729-6There is no corresponding record for this reference.
- 8Hemond, H. F.; Lin, K. Nitrate Suppresses Internal Phosphorus Loading in an Eutrophic Lake. Water Res. 2010, 44 (12), 3645– 3650, DOI: 10.1016/j.watres.2010.04.018There is no corresponding record for this reference.
- 9Yan, J.; Xu, H.; Chang, L.; Lin, A.; Cheng, D. Revealing the pH-Dependent Mechanism of Nitrate Electrochemical Reduction to Ammonia on Single-Atom Catalysts. Nanoscale 2022, 14 (41), 15422– 15431, DOI: 10.1039/D2NR02545KThere is no corresponding record for this reference.
- 10Sheldon, R. A.; Woodley, J. M. Role of Biocatalysis in Sustainable Chemistry. Chem. Rev. 2018, 118 (2), 801– 838, DOI: 10.1021/acs.chemrev.7b0020310https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsVeqt73P&md5=f38e1ba13fb6bd8626751cbd31af8b8fRole of Biocatalysis in Sustainable ChemistrySheldon, Roger A.; Woodley, John M.Chemical Reviews (Washington, DC, United States) (2018), 118 (2), 801-838CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)A review. Based on the principles and metrics of green chem. and sustainable development, biocatalysis is both a green and sustainable technol. This is largely a result of the spectacular advances in mol. biol. and biotechnol. achieved in the last two decades. Protein engineering has enabled the optimization of existing enzymes and the invention of entirely new biocatalytic reactions that were previously unknown in Nature. It is now eminently feasible to develop enzymic transformations to fit predefined parameters, resulting in processes that are truly sustainable by design. This has successfully been applied, for example, in the industrial synthesis of active pharmaceutical ingredients. In addn. to the use of protein engineering, other aspects of biocatalysis engineering, such as substrate, medium and reactor engineering, can be utilized to improve the efficiency, cost-effectiveness and, hence, the sustainability of biocatalytic reactions. Furthermore, immobilization of an enzyme can improve its stability and enable its reuse multiple times, resulting in a better performance and com. viability. Consequently, biocatalysis is being widely applied in the prodn. of pharmaceuticals and in some commodity chems. Moreover, its broader application will be further stimulated in the future by the emerging biobased economy.
- 11Li, Y.; Qiao, S.; Guo, M.; Hou, C.; Wang, J.; Yu, C.; Zhou, J.; Quan, X. Microbial Electrosynthetic Nitrate Reduction to Ammonia by Reversing the Typical Electron Transfer Pathway in Shewanella oneidensis. Cell Rep. Phys. Sci. 2023, 4 (6), 101433 DOI: 10.1016/j.xcrp.2023.101433There is no corresponding record for this reference.
- 12Schwalb, C.; Chapman, S. K.; Reid, G. A. The Membrane-Bound Tetrahaem c-Type Cytochrome Cym A Interacts Directly with the Soluble Fumarate Reductase in Shewanella. Biochem. Soc. Trans. 2002, 30 (4), 658– 662, DOI: 10.1042/bst0300658There is no corresponding record for this reference.
- 13Yu, Y.-Y.; Wang, Y.-Z.; Fang, Z.; Shi, Y.-T.; Cheng, Q.-W.; Chen, Y.-X.; Shi, W.; Yong, Y.-C. Single Cell Electron Collectors for Highly Efficient Wiring-up Electronic Abiotic/Biotic Interfaces. Nat. Commun. 2020, 11 (1), 4087, DOI: 10.1038/s41467-020-17897-913https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhs1Crtr7L&md5=0d95f39117becf6348de710549a6b46eSingle cell electron collectors for highly efficient wiring-up electronic abiotic/biotic interfacesYu, Yang-Yang; Wang, Yan-Zhai; Fang, Zhen; Shi, Yu-Tong; Cheng, Qian-Wen; Chen, Yu-Xuan; Shi, Weidong; Yong, Yang-ChunNature Communications (2020), 11 (1), 4087CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)By electronically wiring-up living cells with abiotic conductive surfaces, bioelectrochem. systems (BES) harvest energy and synthesize elec.-/solar-chems. with unmatched thermodn. efficiency. However, the establishment of an efficient electronic interface between living cells and abiotic surfaces is hindered due to the requirement of extremely close contact and high interfacial area, which is quite challenging for cell and material engineering. Herein, we propose a new concept of a single cell electron collector, which is in-situ built with an interconnected intact conductive layer on and cross the individual cell membrane. The single cell electron collector forms intimate contact with the cellular electron transfer machinery and maximizes the interfacial area, achieving record-high interfacial electron transfer efficiency and BES performance. Thus, this single cell electron collector provides a superior tool to wire living cells with abiotic surfaces at the single-cell level and adds new dimensions for abiotic/biotic interface engineering.
- 14Beinert, H. Iron-Sulfur Proteins: Ancient Structures, Still Full of Surprises. JBIC J. Biol. Inorg. Chem. 2000, 5 (1), 2– 15, DOI: 10.1007/s00775005000214https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXitVyktb4%253D&md5=43d370fa3f991c4bb303d092ea614f5bIron-sulfur proteins: ancient structures, still full of surprisesBeinert, HelmutJBIC, Journal of Biological Inorganic Chemistry (2000), 5 (1), 2-15CODEN: JJBCFA; ISSN:0949-8257. (Springer-Verlag)A review with 59 refs. The properties and functions of Fe-S proteins are surveyed under the following headings: S and Fe; Fe-S clusters; evolution of cofactor use; early observations; complex and extended clusters; S-exchange and core interconversions; synthesis and biosynthesis of Fe-S clusters; functions of Fe-S clusters: electron transfer, electron delocalization, spin states and magnetism, covalency of S bonds; non-electron transfer functions of Fe-S clusters: substrate binding and catalysis, and regulatory and sensing functions.
- 15Han, Y.; Liao, C.; Meng, X.; Zhao, Q.; Yan, X.; Tian, L.; Liu, Y.; Li, N.; Wang, X. Switchover of Electrotrophic and Heterotrophic Respirations Enables the Biomonitoring of Low Concentration of BOD in Oxygen-Rich Environment. Water Res. 2023, 235, 119897 DOI: 10.1016/j.watres.2023.11989715https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXmt1ahtrs%253D&md5=85861cb405fa873a43313efc1ee23a7aSwitchover of electrotrophic and heterotrophic respirations enables the biomonitoring of low concentration of BOD in oxygen-rich environmentHan, Yilian; Liao, Chengmei; Meng, Xinyi; Zhao, Qian; Yan, Xuejun; Tian, Lili; Liu, Ying; Li, Nan; Wang, XinWater Research (2023), 235 (), 119897CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)BOD (BOD) is a key indicator of water quality. However, there is still no technique to directly measure BOD at low concns. in oxygen-rich environments. Here, we propose a new scheme using facultative electrotrophs as the sensing element, and confirmed aerobic Acinetobacter venetianus RAG-1 immobilized on electrode was able to measure BOD via the switchover between electrotrophic and heterotrophic respirations. The hybrid binder of Nafion and polytetrafluoroethylene (PTFE) maximized the baseline current (127 ± 2 A/m2) and sensitivity (2.5 ± 0.1 (mA/m2)/(mg/L)). The current decrease and the BOD5 concn. fitted well with a linear model in the case of known contaminants, verified with both lab samples of acetate and glucose (R2>0.96) and in std. curves of real environmental samples collected from the lake and the effluent of wastewater treatment plant (R2>0.98). Importantly, the biosensor tested actual contaminated water samples with an error of 0.4∼10% compared to BOD5 in the case of unknown contaminants. Transcriptomics revealed that reverse oxidative TCA may involve in the electrotrophic respiration of RAG-1 since citrate synthase (gltA) was highly expressed, which was partly downregulated when heterotrophic metab. was triggered by BOD. This can be returned to electrotroph when BOD was depleted. Our results showed a new way to rapidly measure BOD in oxygen-rich environment, demonstrating the possibility to employ bacteria with two competitive respiration pathways for pollution detection.
- 16Yang, W.; Zhou, M.; Oturan, N.; Bechelany, M.; Cretin, M.; Oturan, M. A. Highly Efficient and Stable FeIIFeIII LDH Carbon Felt Cathode for Removal of Pharmaceutical Ofloxacin at Neutral pH. J. Hazard. Mater. 2020, 393, 122513 DOI: 10.1016/j.jhazmat.2020.12251316https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXltF2nsr0%253D&md5=341e78b12d2b16e83f29184922064ab1Highly efficient and stable FeIIFeIII LDH carbon felt cathode for removal of pharmaceutical ofloxacin at neutral pHYang, Weilu; Zhou, Minghua; Oturan, Nihal; Bechelany, Mikhael; Cretin, Marc; Oturan, Mehmet A.Journal of Hazardous Materials (2020), 393 (), 122513CODEN: JHMAD9; ISSN:0304-3894. (Elsevier B.V.)The traditional electro-Fenton (EF) has been facing major challenges including narrow suitable range of pH and non-reusability of catalyst. To overcome these drawbacks we synthesized FeIIFeIII-layered double hydroxide modified carbon felt (FeIIFeIII LDH-CF) cathode via in situ solvo-thermal process. Chem. compn. and electrochem. characterization of FeIIFeIII LDH-CF were tested and analyzed. The apparent rate const. of decay kinetics of ofloxacin (OFC) with FeIIFeIII LDH-CF (0.18 min-1) at pH 7 was more than 3 times higher than that of homogeneous EF (0.05 min-1) at pH 3 with 0.1 mM Fe2+ under same c.d. (9.37 mA cm-2). Also, a series of expts. including evolution of soln. pH, iron leaching, OFC removal with trapping agent and quant. detection of hydroxyl radicals (·OH) were conducted, demonstrating the dominant role of ·OH generated by surface catalyst via ≃ FeII/FeIII on LDH cathode for degrdn. of orgs. as well contributing to high efficiency and good stability at neutral pH. Besides, formation and evolution of arom. intermediates, carboxylic acids and inorg. ions (F-, NH4+ and NO3-) were identified by High-Performance Liq. chromatog., Gas Chromatog.-Mass Spectrometry and ionic chromatog. analyses. These findings allowed proposing a plausible degrdn. pathway of OFC by ·OH generated in the heterogeneous EF process.
- 17Jiao, K.; Xuan, J.; Du, Q.; Bao, Z.; Xie, B.; Wang, B.; Zhao, Y.; Fan, L.; Wang, H.; Hou, Z.; Huo, S.; Brandon, N. P.; Yin, Y.; Guiver, M. D. Designing the next Generation of Proton-Exchange Membrane Fuel Cells. Nature 2021, 595 (7867), 361– 369, DOI: 10.1038/s41586-021-03482-717https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhsFGqtrvL&md5=a1626e0aeec3bf0d0e3daecced15ba35Designing the next generation of proton-exchange membrane fuel cellsJiao, Kui; Xuan, Jin; Du, Qing; Bao, Zhiming; Xie, Biao; Wang, Bowen; Zhao, Yan; Fan, Linhao; Wang, Huizhi; Hou, Zhongjun; Huo, Sen; Brandon, Nigel P.; Yin, Yan; Guiver, Michael D.Nature (London, United Kingdom) (2021), 595 (7867), 361-369CODEN: NATUAS; ISSN:0028-0836. (Nature Portfolio)Abstr.: With the rapid growth and development of proton-exchange membrane fuel cell (PEMFC) technol., there has been increasing demand for clean and sustainable global energy applications. Of the many device-level and infrastructure challenges that need to be overcome before wide commercialization can be realized, one of the most crit. ones is increasing the PEMFC power d., and ambitious goals have been proposed globally. For example, the short- and long-term power d. goals of Japan's New Energy and Industrial Technol. Development Organization are 6 kW per L by 2030 and 9 kW per L by 2040, resp. To this end, here we propose tech. development directions for next-generation high-power-d. PEMFCs. We present the latest ideas for improvements in the membrane electrode assembly and its components with regard to water and thermal management and materials. These concepts are expected to be implemented in next-generation PEMFCs to achieve high power d.
- 18Kempers, A. J.; Zweers, A. Ammonium Determination in Soil Extracts by the Salicylate Method. Commun. Soil Sci. Plant Anal. 1986, 17 (7), 715– 723, DOI: 10.1080/00103628609367745There is no corresponding record for this reference.
- 19Shinn, M. B. Colorimetric Method for Determination of Nitrate. Ind. Eng. Chem. Anal. Ed. 1941, 13 (1), 33– 35, DOI: 10.1021/i560089a01019https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaH3MXosV2l&md5=02c42c7720ecec925a8029f3d4e6697aColorimetric method for determination of nitriteShinn, Martha B.Industrial and Engineering Chemistry, Analytical Edition (1941), 13 (), 33-5CODEN: IENAAD; ISSN:0096-4484.Sulfanilamide in 0.2% aq. soln. and a 0.1% aq. soln. (I) of N-(1-naphthyl)ethylenediamine dihydrochloride are superior to sulfanilic acid and α-naphthylamine for the colorimetric detn. of nitrite. The color is clearer, reaches its max. more rapidly and remains stable for a longer time. A standardized soln. of sulfanilamide is substituted for NaNO2 as a primary standard. The soln. for analysis can be neutral or up to 1 N in acid. Not more than 0.05 mg. of nitrite should be present and the vol. not over 35 ml. To the unknown add 1 ml. of 6 N HCl, 5 ml. of the sulfanilamide soln. and allow to stand 3 min. Add 1 ml. of 0.5% soln. of NH4 sulfamate and let stand 2 min. Then add 1 ml. of I and dil. to exactly 50 ml. and mix. At the same time prep. a nitrite standard from the sulfanilamide soln. by reduction with NaNO3 in dil. HCl.
- 20Fu, X.-Z.; Li, J.; Pan, X.-R.; Huang, L.; Li, C.-X.; Cui, S.; Liu, H.-Q.; Tan, Z.-L.; Li, W.-W. A Single Microbial Electrochemical System for CO2 Reduction and Simultaneous Biogas Purification. Upgrading and Sulfur Recovery. Bioresour. Technol. 2020, 297, 122448 DOI: 10.1016/j.biortech.2019.122448There is no corresponding record for this reference.
- 21Yu, Y.-Y.; Cheng, Q.-W.; Sha, C.; Chen, Y.-X.; Naraginti, S.; Yong, Y.-C. Size-Controlled Biosynthesis of FeS Nanoparticles for Efficient Removal of Aqueous Cr(VI). Chem. Eng. J. 2020, 379, 122404 DOI: 10.1016/j.cej.2019.12240421https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsFKhtL%252FL&md5=516d08d7b236c9c535f1b01a36189815Size-controlled biosynthesis of FeS nanoparticles for efficient removal of aqueous Cr(VI)Yu, Yang-Yang; Cheng, Qian-Wen; Sha, Chong; Chen, Yu-Xuan; Naraginti, Saraschandra; Yong, Yang-ChunChemical Engineering Journal (Amsterdam, Netherlands) (2020), 379 (), 122404CODEN: CMEJAJ; ISSN:1385-8947. (Elsevier B.V.)In this study, biogenic iron sulfide nanoparticles (FeS NPs) were synthesized by Shewanella and used for Cr(VI) removal. To control the size of FeS NPs, the biol. S(-II) releasing rate was proposed as the key parameter in Fe(III) redn. and was subtly tuned with the aid of a kinetic model. Field emission scanning electron microscope (FESEM) observation revealed that gradually increased S(-II) releasing rate lead to the formation of FeS NPs with size from 30 nm to 90 nm. Impressively, the biogenic FeS NPs with 30-40 nm showed high removal rate and large removal capacity (565.6 mg/g) for removal of aq. Cr(VI). Further analyses revealed that the improved performance of small FeS NPs was ascribed to the reduced passivation of FeS. Therefore, this study provided a facile approach for size-controlled biosynthesis of FeS NPs, and demonstrated the promise to use biogenic FeS NPs for chromate remediation.
- 22Zhou, C.; Zhou, Y.; Rittmann, B. E. Reductive Precipitation of Sulfate and Soluble Fe(III) by Desulfovibrio Vulgaris: Electron Donor Regulates Intracellular Electron Flow and Nano-FeS Crystallization. Water Res. 2017, 119, 91– 101, DOI: 10.1016/j.watres.2017.04.04422https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXmsFertbw%253D&md5=0621ade89585258bb4c276acba975c36Reductive precipitation of sulfate and soluble Fe(III) by Desulfovibrio vulgaris: Electron donor regulates intracellular electron flow and nano-FeS crystallizationZhou, Chen; Zhou, Yun; Rittmann, Bruce E.Water Research (2017), 119 (), 91-101CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)Fully understanding the metab. of SRB provides fundamental guidelines for allowing the microorganisms to provide more beneficial services in water treatment and resource recovery. The electron-transfer pathway of sulfate respiration by Desulfovibrio vulgaris is well studied, but still partly unresolved. Here we provide deeper insight by comprehensively monitoring metabolite changes during D. vulgaris metab. with two electron donors, lactate and pyruvate, in presence or absence of citrate-chelated sol. FeIII as an addnl. competing electron acceptor. H2 was produced from lactate oxidn. to pyruvate, but pyruvate oxidn. produced mostly formate. Accumulation of lactate-originated H2 during lag phases inhibited pyruvate transformation to acetate. Sulfate redn. was initiated by lactate-originated H2, but MQ-mediated e- flow initiated sulfate redn. without delay when pyruvate was the donor. When H2-induced electron flow gave priority to FeIII redn. over sulfate redn., the long lag phase before sulfate redn. shortened the time for iron-sulfide crystallite growth and led to smaller mackinawite (Fe1+xS) nanocrystallites. Synthesizing all the results, we propose that electron flow from lactate or pyruvate towards SO2-4 redn. to H2S are through at least three routes that are regulated by the e- donor (lactate or pyruvate) and the presence or absence of another e- acceptor (FeIII here). These routes are not competing, but complementary: e.g., H2 or formate prodn. and oxidn. were necessary for sulfite and disulfide/trisulfide redn. to sulfide. Our study suggests that the e- donor provides a practical tool to regulate and optimize SRB-predominant bioremediation systems.
- 23Fu, X.-Z.; Wu, J.; Cui, S.; Wang, X.-M.; Liu, H.-Q.; He, R.-L.; Yang, C.; Deng, X.; Tan, Z.-L.; Li, W.-W. Self-Regenerable Bio-Hybrid with Biogenic Ferrous Sulfide Nanoparticles for Treating High-Concentration Chromium-Containing Wastewater. Water Res. 2021, 206, 117731 DOI: 10.1016/j.watres.2021.11773123https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXitF2htbnF&md5=d7a03b122ee0f9f9b0284e9af2002df3Self-regenerable bio-hybrid with biogenic ferrous sulfide nanoparticles for treating high-concentration chromium-containing wastewaterFu, Xian-Zhong; Wu, Jie; Cui, Shuo; Wang, Xue-Meng; Liu, Hou-Qi; He, Ru-Li; Yang, Cheng; Deng, Xin; Tan, Zhou-Liang; Li, Wen-WeiWater Research (2021), 206 (), 117731CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)Biogenic ferrous sulfide nanoparticles (bio-FeS) as low-cost and green-synthesized nanomaterial are promising for heavy metals removal, but the need for complicated extn., storage processes and the prodn. of iron sludge still restrict their practical application. Here, a self-regenerable bio-hybrid consisting of bacterial cells and self-assembled bio-FeS was developed to efficiently remove chromium (Cr(VI)). A dense layer of bio-FeS was distributed on the cell surface and in the periplasmic space of Shewanella oneidensis MR-1, endowing the bacterium with good Cr(VI) tolerance and unusual activity for bio-FeS-mediated Cr(VI) redn. An artificial transmembrane electron channel was constituted by the bio-FeS to facilitate extracellular electron pumping, enabling efficient regeneration of extracellular bio-FeS for continuous Cr(VI) redn. The bio-hybrid maintained high activity within three consecutive treatment-regeneration cycles for treating both simulated Cr(VI)-contg. wastewater (50 mg/L) and real electroplating wastewater. Importantly, its activity can be facilely and fully restored through bio-FeS re-synthesis or regeneration with replenished fresh bacteria. Overall, the bio-hybrid merges the self-regeneration ability of bacteria with high activity of bio-FeS , opening a promising new avenue for sustainable treatment of heavy metal- contg. wastewater.
- 24Rowe, A. R.; Rajeev, P.; Jain, A.; Pirbadian, S.; Okamoto, A.; Jeffrey, A.; El-Naggar, Y.; Nealson, Kenneth H. Tracking Electron Uptake from a Cathode into Shewanella Cells: Implications for Energy Acquisition from Solid-Substrate Electron Donors. mBio 2018, 9 (1), e02203 DOI: 10.1128/mbio.02203-17There is no corresponding record for this reference.
- 25Meshulam-Simon, G.; Behrens, S.; Choo, A. D.; Spormann, A. M. Hydrogen Metabolism in Shewanella oneidensis MR-1. Appl. Environ. Microbiol. 2007, 73 (4), 1153– 1165, DOI: 10.1128/AEM.01588-0625https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXitlyqsb0%253D&md5=5d70a37aab97fa74ecea36d46519313eHydrogen metabolism in Shewanella oneidensis MR-1Meshulam-Simon, Galit; Behrens, Sebastian; Choo, Alexander D.; Spormann, Alfred M.Applied and Environmental Microbiology (2007), 73 (4), 1153-1165CODEN: AEMIDF; ISSN:0099-2240. (American Society for Microbiology)Shewanella oneidensis MR-1 is a facultative sediment microorganism which uses diverse compds., such as oxygen and fumarate, as well as insol. Fe(III) and Mn(IV) as electron acceptors. The electron donor spectrum is more limited and includes metabolic end products of primary fermenting bacteria, such as lactate, formate, and hydrogen. While the utilization of hydrogen as an electron donor has been described previously, we report here the formation of hydrogen from pyruvate under anaerobic, stationary-phase conditions in the absence of an external electron acceptor. Genes for the two S. oneidensis MR-1 hydrogenases, hydA, encoding a periplasmic [Fe-Fe] hydrogenase, and hyaB, encoding a periplasmic [Ni-Fe] hydrogenase, were found to be expressed only under anaerobic conditions during early exponential growth and into stationary-phase growth. Analyses of ΔhydA, ΔhyaB, and ΔhydA ΔhyaB in-frame-deletion mutants indicated that HydA functions primarily as a hydrogen-forming hydrogenase while HyaB has a bifunctional role and represents the dominant hydrogenase activity under the exptl. conditions tested. Based on results from physiol. and genetic expts., we propose that hydrogen is formed from pyruvate by multiple parallel pathways, one pathway involving formate as an intermediate, pyruvate-formate lyase, and formate-hydrogen lyase, comprised of HydA hydrogenase and formate dehydrogenase, and a formate-independent pathway involving pyruvate dehydrogenase. A reverse electron transport chain is potentially involved in a formate-hydrogen lyase-independent pathway. While pyruvate does not support a fermentative mode of growth in this microorganism, pyruvate, in the absence of an electron acceptor, increased cell viability in anaerobic, stationary-phase cultures, suggesting a role in the survival of S. oneidensis MR-1 under stationary-phase conditions.
- 26Cruz-García, C.; Murray, A. E.; Klappenbach, J. A.; Stewart, V.; Tiedje, J. M. Respiratory Nitrate Ammonification by Shewanella oneidensis MR-1. J. Bacteriol. 2007, 189 (2), 656– 662, DOI: 10.1128/JB.01194-0626https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXpt1WqtQ%253D%253D&md5=c9540071da0ab68c7e2e26401e4a597eRespiratory nitrate ammonification by Shewanella oneidensis MR-1Cruz-Garcia, Claribel; Murray, Alison E.; Klappenbach, Joel A.; Stewart, Valley; Tiedje, James M.Journal of Bacteriology (2007), 189 (2), 656-662CODEN: JOBAAY; ISSN:0021-9193. (American Society for Microbiology)Anaerobic cultures of Shewanella oneidensis MR-1 grown with nitrate as the sole electron acceptor exhibited sequential redn. of nitrate to nitrite and then to ammonium. Little dinitrogen and nitrous oxide were detected, and no growth occurred on nitrous oxide. A mutant with the napA gene encoding periplasmic nitrate reductase deleted could not respire or assimilate nitrate and did not express nitrate reductase activity, confirming that the NapA enzyme is the sole nitrate reductase. Hence, S. oneidensis MR-1 conducts respiratory nitrate ammonification, also termed dissimilatory nitrate redn. to ammonium, but not respiratory denitrification.
tiejej@msu.edu.
- 27Han, H.-X.; Tian, L.-J.; Liu, D.-F.; Yu, H.-Q.; Sheng, G.-P.; Xiong, Y. Reversing Electron Transfer Chain for Light-Driven Hydrogen Production in Biotic–Abiotic Hybrid Systems. J. Am. Chem. Soc. 2022, 144, 6434, DOI: 10.1021/jacs.2c0093427https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XovVSiurs%253D&md5=b79956f07000ec63ee949c8b021fbf79Reversing electron transfer chain for light-driven hydrogen production in biotic-abiotic hybrid systemsHan, He-Xing; Tian, Li-Jiao; Liu, Dong-Feng; Yu, Han-Qing; Sheng, Guo-Ping; Xiong, YujieJournal of the American Chemical Society (2022), 144 (14), 6434-6441CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)The biotic-abiotic photosynthetic system integrating inorg. light absorbers with whole-cell biocatalysts innovates the way for sustainable solar-driven chem. transformation. Fundamentally, the electron transfer at the biotic-abiotic interface, which may induce biol. response to photoexcited electron stimuli, plays an essential role in solar energy conversion. Herein, we selected an electro-active bacterium Shewanella oneidensis MR-1 as a model, which constitutes a hybrid photosynthetic system with a self-assembled CdS semiconductor, to demonstrate unique biotic-abiotic interfacial behavior. The photoexcited electrons from CdS nanoparticles can reverse the extracellular electron transfer (EET) chain within S. oneidensis MR-1, realizing the activation of a bacterial catalytic network with light illumination. As compared with bare S. oneidensis MR-1, a significant upregulation of hydrogen yield (711-fold), ATP, and reducing equiv. (NADH/NAD+) was achieved in the S. oneidensis MR-1-CdS under visible light. This work sheds light on the fundamental mechanism and provides design guidelines for biotic-abiotic photosynthetic systems.
- 28Xiao, X.; Li, C.-X.; Peng, J.-R.; Fan, Y.-Y.; Li, W.-W. Dynamic Roles of Inner Membrane Electron-Transfer Hub of Shewanella oneidensis MR-1 in Response to Extracellular Reduction Kinetics. Chem. Eng. J. 2023, 451, 138717 DOI: 10.1016/j.cej.2022.13871728https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xit1emt7jE&md5=ce2eaf982902ecc549cb7a727f983f38Dynamic roles of inner membrane electron-transfer hub of Shewanella oneidensis MR-1 in response to extracellular reduction kineticsXiao, Xiang; Li, Chang-Xing; Peng, Jie-Ru; Fan, Yang-Yang; Li, Wen-WeiChemical Engineering Journal (Amsterdam, Netherlands) (2023), 451 (Part_2), 138717CODEN: CMEJAJ; ISSN:1385-8947. (Elsevier B.V.)The unique extracellular electron transfer (EET) network of exoelectrogens endow them with extraordinary extracellular respiration ability to facilitate environmental remediation and biogeochem. processes. Shewanella oneidensis MR-1 is an environmentally ubiquitous exoelectrogen possessing multiple EET pathways. While the inner membrane CymA protein is widely believed to serve as an essential electron transfer hub in all these pathways, here our exptl. evidences suggest another possibility: its EET role is highly dependent on extracellular redn. kinetics. Comparison of the bacterial EET and extracellular redn. performances in response to different species and concns. of extracellular electron acceptors shows that the fraction of electron efflux contributed by the CymA pathway is pos. correlated to the EET rate. This means some unknown EET pathways independent of CymA are activated under slow EET condition, likely as a strategy of self-adaptation to environmental changes by feedback regulating the electron transport pathways. Our findings provide a new perspective to facilitate better understanding of the dynamic bacteria-environment interactions, and may inspire the discovery of new EET proteins and the development of more environmentally-robust biotechnologies for environmental remediation applications.
- 29Schwalb, C.; Chapman, S. K.; Reid, G. A. The tetraheme Cytochrome CymA Is Required for Anaerobic Respiration with Dimethyl Sulfoxide and Nitrite in Shewanella oneidensis. Biochemistry 2003, 42 (31), 9491– 9497, DOI: 10.1021/bi034456f29https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXlsVGiu7o%253D&md5=f54aba4645eff55aec601947fc27cc6fThe Tetraheme Cytochrome CymA Is Required for Anaerobic Respiration with Dimethyl Sulfoxide and Nitrite in Shewanella oneidensisSchwalb, Carsten; Chapman, Stephen K.; Reid, Graeme A.Biochemistry (2003), 42 (31), 9491-9497CODEN: BICHAW; ISSN:0006-2960. (American Chemical Society)The tetraheme c-type cytochrome, CymA, from Shewanella oneidensis MR-1 has previously been shown to be required for respiration with Fe(III), nitrate, and fumarate. It is located in the cytoplasmic membrane where the bulk of the protein is exposed to the periplasm, enabling it to transfer electrons to a series of redox partners. The authors have expressed and purified a sol. deriv. of CymA (CymAsol) that lacks the N-terminal membrane anchor. The authors show here, by direct measurements of electron transfer between the purified proteins, that CymAsol efficiently reduces S. oneidensis fumarate reductase. This indicates that no further proteins are required for electron transfer between the quinone pool and fumarate if the authors assume direct redn. of CymA by quinols. By expressing CymAsol in a mutant lacking CymA, the authors have shown that this sol. form of the protein can complement the defect in fumarate respiration. The authors also demonstrate that CymA is essential for growth with DMSO and for redn. of nitrite, implicating CymA in at least five different electron transfer pathways in Shewanella.
- 30Logan, B. E.; Hamelers, B.; Rozendal, R.; Schröder, U.; Keller, J.; Freguia, S.; Aelterman, P.; Verstraete, W.; Rabaey, K. Microbial Fuel Cells: Methodology and Technology. Environ. Sci. Technol. 2006, 40 (17), 5181– 5192, DOI: 10.1021/es060501630https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XmvVeisrs%253D&md5=136609c45b85681f70d4e0a0d5eab061Microbial Fuel Cells: Methodology and TechnologyLogan, Bruce E.; Hamelers, Bert; Rozendal, Rene; Schroeder, Uwe; Keller, Juerg; Freguia, Stefano; Aelterman, Peter; Verstraete, Willy; Rabaey, KorneelEnvironmental Science & Technology (2006), 40 (17), 5181-5192CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)A review of the different materials and methods used to construct a microbial fuel cell (MFC), techniques used to analyze system performance, with recommendations on what information to include in MFC studies and useful ways to present results. MFC research is an evolving field that lacks established terminol. and methods for the anal. of system performance. This makes it difficult for researchers to compare devices. The construction and anal. of MFCs requires knowledge of different scientific and engineering fields, ranging from microbiol. and electrochem. to materials and environmental engineering. Describing MFC systems therefore involves an understanding of these different scientific and engineering principles.
- 31Li, X.-M.; Ding, L.-J.; Zhu, D.; Zhu, Y.-G. Long-Term Fertilization Shapes the Putative Electrotrophic Microbial Community in Paddy Soils Revealed by Microbial Electrosynthesis Systems. Environ. Sci. Technol. 2021, 55 (5), 3430– 3441, DOI: 10.1021/acs.est.0c0802231https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXkt1Oqur4%253D&md5=e379089c6f4395af3d065186756dafe6Long-Term Fertilization Shapes the Putative Electrotrophic Microbial Community in Paddy Soils Revealed by Microbial Electrosynthesis SystemsLi, Xiao-Min; Ding, Long-Jun; Zhu, Dong; Zhu, Yong-GuanEnvironmental Science & Technology (2021), 55 (5), 3430-3441CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Electrotrophs play an important role in biogeochem. cycles, but the effects of long-term fertilization on electrotrophic communities in paddy soils remain unclear. Here, we explored the responses of electrotrophic communities in paddy soil-based microcosms to different long-term fertilization practices using microbial electrosynthesis systems (MESs), high-throughput quant. PCR, and 16s rRNA gene-based Illumina sequencing techniques. Compared to the case in the unfertilized soil (CK), applications of only manure (M); only chem. nitrogen, phosphorous, and potassium fertilizers (NPK); and M plus NPK (MNPK) clearly changed the electrotrophic bacterial community structure. The Streptomyces genus of the Actinobacteria phylum was the dominant electrotroph in the CK, M, and MNPK soils. The latter two soils also favored Truepera of Deinococcus-Thermus or Arenimonas and Thioalkalispira of Proteobacteria. Furthermore, Pseudomonas of Proteobacteria and Bacillus of Firmicutes were major electrotrophs in the NPK soil. These electrotrophs consumed biocathodic currents coupled with nitrate redn. and recovered 18-38% of electrons via dissimilatory nitrate redn. to ammonium (DNRA). The increased abundances of the nrfA gene for DNRA induced by elec. potential further supported that the electrotrophs enhanced DNRA for all soils. These expand our knowledge about the diversity of electrotrophs and their roles in N cycle in paddy soils and highlight the importance of fertilization in shaping electrotrophic communities. The 16S rRNA gene-based sequencing data have been deposited to the NCBI SRA under the accession nos. PRJNA600772, SAMN13831192 to SAMN13831215.
- 32Wu, Y.; Du, Q.; Wan, Y.; Zhao, Q.; Li, N.; Wang, X. Autotrophic Nitrate Reduction to Ammonium via Reverse Electron Transfer in Geobacter Dominated Biofilm. Biosens. Bioelectron. 2022, 215, 114578 DOI: 10.1016/j.bios.2022.11457832https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XitVWksb%252FN&md5=a6ebe0a4cf27ce20051e9c4a5ab78366Autotrophic nitrate reduction to ammonium via reverse electron transfer in Geobacter dominated biofilmWu, Yue; Du, Qing; Wan, Yuxuan; Zhao, Qian; Li, Nan; Wang, XinBiosensors & Bioelectronics (2022), 215 (), 114578CODEN: BBIOE4; ISSN:0956-5663. (Elsevier B.V.)Geobacter dominated electroactive biofilms (EABs) have been demonstrated to perform bidirectional extracellular electron transfer (EET) in bioelectrochem. systems, but it is largely unknown when nitrate is the electron acceptor at the cathode. If reverse EET occurs on biocathode, this EAB has to perform dissimilatory nitrate redn. to ammonia (DNRA) rather than denitrification according to genomes. Here, we have proven the feasibility of reverse bioelectron transfer in EAB, achieving a DNRA efficiency up to 93 ± 3% and high Faraday efficiency of 74 ± 1%. Const. current was found to be more effective than const. potential to maintain Geobacter on the cathode, which highly dets. this electrotrophic respiration. The prevalent DNRA at const. current surpassed denitrification, demonstrated by the reverse tendencies of DNRA (nrfA) and denitrification (nirS anirK) gene transcription. Metatranscriptomics further revealed the possible electron uptake mechanisms by which the outer membrane (OmcZ and OmcB) and periplasmic cytochromes (PpcB and PpcD) may be involved. These findings extend our understanding of the bidirectional electron transfer and advance the applications of EABs.
- 33Su, W.; Zhang, L.; Li, D.; Zhan, G.; Qian, J.; Tao, Y. dissimilatory Nitrate Reduction by Pseudomonas Alcaliphila with an Electrode as the Sole Electron Donor. Biotechnol. Bioeng. 2012, 109 (11), 2904– 2910, DOI: 10.1002/bit.2455433https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XnslOisbY%253D&md5=37fc545503048e1b83907ac43191e682Dissimilatory nitrate reduction by Pseudomonas alcaliphila with an electrode as the sole electron donorSu, Wentao; Zhang, Lixia; Li, Daping; Zhan, Guoqiang; Qian, Junwei; Tao, YongBiotechnology and Bioengineering (2012), 109 (11), 2904-2910CODEN: BIBIAU; ISSN:0006-3592. (John Wiley & Sons, Inc.)Denitrification and dissimilatory nitrate redn. to ammonium (DNRA) were considered two alternative pathways of dissimilatory nitrate redn. In this study, we firstly reported that both denitrification and DNRA occurred in Pseudomonas alcaliphila strain MBR with an electrode as the sole electron donor in a double chamber bio-electrochem. system (BES). The initial concn. of nitrate appeared as a factor detg. the type of nitrate redn. with electrode as the sole electron donor at the same potential (-500 mV). As the initial concn. of nitrate increased, the fraction of nitrate reduced through denitrification also increased. While nitrite (1.38 ± 0.04 mM) was used as electron acceptor instead of nitrate, the electrons recovery via DNRA and denitrification were 43.06 ± 1.02% and 50.51 ± 1.37%, resp. The electrochem. activities and surface topog. of the working electrode catalyzed by strain MBR were evaluated by cyclic voltammetry and SEM. The results suggested that cells of strain MBR were adhered to the electrode, playing the role of electron transfer media for nitrate and nitrite redn. Thus, for the first time, the results that DNRA and denitrification occurred simultaneously were confirmed by powering the strain with electricity. The study further expanded the range of metabolic reactions and had potential value for the recognization of dissimilatory nitrate redn. in various ecosystems. Biotechnol. Bioeng. © 2012 Wiley Periodicals, Inc.
- 34Liang, D.; Li, C.; He, W.; Li, Z.; Feng, Y. Response of Exoelectrogens Centered Consortium to Nitrate on Collaborative Metabolism, Microbial Community, and Spatial Structure. Chem. Eng. J. 2021, 426, 130975 DOI: 10.1016/j.cej.2021.130975There is no corresponding record for this reference.
- 35Liang, D.; He, W.; Li, C.; Wang, F.; Crittenden, J. C.; Feng, Y. Remediation of Nitrate Contamination by Membrane Hydrogenotrophic Denitrifying Biofilm Integrated in Microbial Electrolysis Cell. Water Res. 2021, 188, 116498 DOI: 10.1016/j.watres.2020.11649835https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXitV2lt7vL&md5=7aa6295cbab2851d9548e8d94f24b812Remediation of nitrate contamination by membrane hydrogenotrophic denitrifying biofilm integrated in microbial electrolysis cellLiang, Dandan; He, Weihua; Li, Chao; Wang, Fei; Crittenden, John C.; Feng, YujieWater Research (2021), 188 (), 116498CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)Complete biol. denitrification is usually restricted in electron donor lacking waters. Hydrogenotrophic denitrification attracts attention for its clean and cost-efficiency advantages. Therein, the hydrogen could be effectively generated by microbial electrolysis cells (MECs) from org. wastes. In this study, a gas diffusion membrane (GDM) integrated MEC (MMEC) was constructed and provided a novel non-polluting approach for nitrate contaminated water remediation, in which the hydrogen was recovered from substrate degrdn. in anode and diffused across GDM as electron donor for denitrification. The high overall nitrogen removal of 91 ± 0.1%-95 ± 1.9% and 90 ± 1.6%-94 ± 2.2% were resp. achieved in Ti-MMEC and SS-MMEC with titanium and stainless-steel mesh as cathode at all applied voltages (0.4-0.8 V). Decreasing applied voltage from 0.8 to 0.4 V significantly improved the electron utilization efficiency for denitrification from 26 ± 3.6% to 73 ±0.1% in Ti-MMEC. Integrating MEC with GDM greatly improved TN removal by 40% under applied voltage of 0.8 V. The hydrogenotrophic denitrifiers of Rhodocyclaceae, Paracoccus, and Dethiobacter, dominated in MMECs facilitating TN removal. Functional denitrification related genes including napAB, nirKS, norBC and nosZ predicted by PICRUSt2 based on 16S rRNA gene data demonstrated higher abundance in MMECs.
- 36Li, F.; Li, F.; Lin, Y.; Guo, L.; Zhang, L.; Li, R.; Tian, Q.; Wang, Y.; Wang, Y.; Zhang, X.; Liu, J.; Fan, C. Investigating the Performance and Mechanism of Nitrogen Gas Fixation and Conversion to Ammonia Based on biocathode bioelectrochemistry System. J. Chem. Technol. Biotechnol. 2022, 97 (8), 2163– 2170, DOI: 10.1002/jctb.7092There is no corresponding record for this reference.
- 37Zhang, L.; Tian, C.; Wang, H.; Gu, W.; Zheng, D.; Cui, M.; Wang, X.; He, X.; Zhan, G.; Li, D. Improving Electroautotrophic Ammonium Production from Nitrogen Gas by Simultaneous Carbon Dioxide Fixation in a Dual–chamber Microbial Electrolysis Cell. bioelectrochemistry 2022, 144, 108044 DOI: 10.1016/j.bioelechem.2021.108044There is no corresponding record for this reference.
- 38Chen, S.; Jing, X.; Yan, Y.; Huang, S.; Liu, X.; Chen, P.; Zhou, S. bioelectrochemical Fixation of Nitrogen to Extracellular Ammonium by Pseudomonas stutzeri. Appl. Environ. Microbiol. 2021, 87 (5), e01998– 20, DOI: 10.1128/AEM.01998-20There is no corresponding record for this reference.
- 39Coursolle, D.; Gralnick, J. A. Modularity of the Mtr Respiratory Pathway of Shewanella oneidensis Strain MR-1. Mol. Microbiol. 2010, 77 (4), 995– 1008, DOI: 10.1111/j.1365-2958.2010.07266.x39https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtFaisrrF&md5=21c610081a0da9a367b67a807107b965Modularity of the Mtr respiratory pathway of Shewanella oneidensis strain MR-1Coursolle, Dan; Gralnick, Jeffrey A.Molecular Microbiology (2010), 77 (4), 995-1008CODEN: MOMIEE; ISSN:0950-382X. (Wiley-Blackwell)Four distinct pathways predicted to facilitate electron flow for respiration of externally located substrates are encoded in the genome of Shewanella oneidensis strain MR-1. Although the pathways share a suite of similar proteins, the activity of only two of these pathways has been described. Respiration of extracellular substrates requires a mechanism to facilitate electron transfer from the quinone pool in the cytoplasmic membrane to terminal reductase enzymes located on the outer leaflet of the outer membrane. The four pathways share MtrA paralogs, a periplasmic electron carrier cytochrome, and terminal reductases similar to MtrC for redn. of metals, flavins and electrodes or to DmsAB for redn. of DMSO. The promiscuity of respiratory electron transfer reactions catalyzed by these pathways has made studying strains lacking single proteins difficult. Here, the authors present a comprehensive anal. of MtrA and MtrC paralogs in S. oneidensis to define the roles of these proteins in respiration of insol. iron oxide, sol. iron citrate, flavins and DMSO. They present evidence that some periplasmic electron carrier components and terminal reductases in these pathways can provide partial compensation in the absence of the primary component, a phenomenon described as modularity, and discuss biochem. and evolutionary implications.
- 40Song, Y. E.; Mohamed, A.; Kim, C.; Kim, M.; Li, S.; Sundstrom, E.; Beyenal, H.; Kim, J. R. Biofilm Matrix and Artificial Mediator for Efficient Electron Transport in CO2Microbial Electrosynthesis. Chem. Eng. J. 2022, 427, 131885 DOI: 10.1016/j.cej.2021.131885There is no corresponding record for this reference.
- 41Yu, C.; Qiao, S.; Zhou, J. Sulfide-Driven Nitrous Oxide Recovery during the Mixotrophic Denitrification Process. J. Environ. Sci. 2023, 125, 443– 452, DOI: 10.1016/j.jes.2021.12.003There is no corresponding record for this reference.
- 42Firer-Sherwood, M.; Pulcu, G. S.; Elliott, S. J. Electrochemical Interrogations of the Mtr cytochromes from Shewanella: Opening a Potential Window. JBIC J. Biol. Inorg. Chem. 2008, 13 (6), 849– 854, DOI: 10.1007/s00775-008-0398-z42https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXovFOmsLw%253D&md5=0e1933c9ac286bc06176fb78dad98993Electrochemical interrogations of the Mtr cytochromes from Shewanella: opening a potential windowFirer-Sherwood, Mackenzie; Pulcu, Goekce Su; Elliott, Sean J.JBIC, Journal of Biological Inorganic Chemistry (2008), 13 (6), 849-854CODEN: JJBCFA; ISSN:0949-8257. (Springer GmbH)The multi-heme cytochromes from Shewanella oneidensis assocd. with the dissimilatory metal redn. (DMR) pathway have been investigated using the technique of protein film voltammetry (PFV). Using PFV, we have interrogated each of the multi-heme cytochromes (MtrA, STC, and solubilized versions of the membrane-bound proteins CymA, OmcA, and MtrC) under identical conditions for the first time. Each cytochrome reveals a broad envelope of voltammetric response, indicative of multiple redox cofactors that span a range of potential of approx. 300 mV. Our studies show that, when considered as an aggregate pathway, the multiple hemes of the DMR cytochromes provide a "window" of operating potential for electron transfer to occur from the cellular interior to the exterior spanning values of -250 to 0 mV (at circumneutral values of pH). Similarly, each cytochrome supports interfacial electron transfer at rates on the order of 200 s-1. These data are taken together to suggest a model of electron transport where a wide window of potential allows for charge transfer from the cellular interior to the exterior to support bioenergetics.
- 43Xiao, Y.; Zhang, E.; Zhang, J.; Dai, Y.; Yang, Z.; Christensen, H. E. M.; Ulstrup, J.; Zhao, F. Extracellular Polymeric Substances Are Transient Media for Microbial Extracellular Electron Transfer. Sci. Adv. 2017, 3 (7), e1700623 DOI: 10.1126/sciadv.170062343https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXntVOlu78%253D&md5=4ff1a579f568ef80f632b757ffd2c384Extracellular polymeric substances are transient media for microbial extracellular electron transferXiao, Yong; Zhang, Enhua; Zhang, Jingdong; Dai, Youfen; Yang, Zhaohui; Christensen, Hans E. M.; Ulstrup, Jens; Zhao, FengScience Advances (2017), 3 (7), e1700623/1-e1700623/8CODEN: SACDAF; ISSN:2375-2548. (American Association for the Advancement of Science)Microorganisms exploit extracellular electron transfer (EET) in growth and information exchange with external environments or with other cells. Every microbial cell is surrounded by extracellular polymeric substances (EPS). Understanding the roles of three-dimensional (3D) EPS in EET is essential in microbiol. and microbial exploitation for mineral bio-respiration, pollutant conversion, and bioenergy prodn. We have addressed these challenges by comparing pure and EPS-depleted samples of three representative electrochem. active strains viz Gram-neg. Shewanella oneidensis MR-1, Gram-pos. Bacillus sp. WS-XY1, and yeast Pichia stipites using technol. from electrochem., spectroscopy, at. force microscopy, and microbiol. Voltammetry discloses redox signals from cytochromes and flavins in intact MR-1 cells, whereas stronger signals from cytochromes and addnl. signals from both flavins and cytochromes are found after EPS depletion. Flow cytometry and fluorescence microscopy substantiated by N-acetylglucosamine and electron transport system activity data showed less than 1.5% cell damage after EPS extn. The electrochem. differences between normal and EPS-depleted cells therefore originate from electrochem. species in cell walls and EPS. The 35 ± 15-nm MR-1 EPS layer is also electrochem. active itself, with cytochrome electron transfer rate consts. of 0.026 and 0.056 s-1 for intact MR-1 and EPS-depleted cells, resp. This surprisingly small rate difference suggests thatmol. redox species at the core of EPS assist EET. The combination of all the data with electron transfer anal. suggests that electron "hopping" is the most likely mol. mechanism for electrochem. electron transfer through EPS.
- 44Marsili, E.; Baron, D. B.; Shikhare, I. D.; Coursolle, D.; Gralnick, J. A.; Bond, D. R. Shewanella Secretes Flavins That Mediate Extracellular Electron Transfer. Proc. Natl. Acad. Sci. U. S. A. 2008, 105 (10), 3968– 3973, DOI: 10.1073/pnas.071052510544https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXjs1Oms7g%253D&md5=0685a57798612487118ba67d026310c5Shewanella secretes flavins that mediate extracellular electron transferMarsili, Enrico; Baron, Daniel B.; Shikhare, Indraneel D.; Coursolle, Dan; Gralnick, Jeffrey A.; Bond, Daniel R.Proceedings of the National Academy of Sciences of the United States of America (2008), 105 (10), 3968-3973CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Bacteria able to transfer electrons to metals are key agents in biogeochem. metal cycling, subsurface bioremediation, and corrosion processes. More recently, these bacteria have gained attention as the transfer of electrons from the cell surface to conductive materials can be used in multiple applications. In this work, we adapted electrochem. techniques to probe intact biofilms of Shewanella oneidensis MR-1 and Shewanella sp. MR-4 grown by using a poised electrode as an electron acceptor. This approach detected redox-active mols. within biofilms, which were involved in electron transfer to the electrode. A combination of methods identified a mixt. of riboflavin and riboflavin-5'-phosphate in supernatants from biofilm reactors, with riboflavin representing the dominant component during sustained incubations (>72 h). Removal of riboflavin from biofilms reduced the rate of electron transfer to electrodes by >70%, consistent with a role as a sol. redox shuttle carrying electrons from the cell surface to external acceptors. Differential pulse voltammetry and cyclic voltammetry revealed a layer of flavins adsorbed to electrodes, even after sol. components were removed, esp. in older biofilms. Riboflavin adsorbed quickly to other surfaces of geochem. interest, such as Fe(III) and Mn(IV) oxy(hydr)oxides. This in situ demonstration of flavin prodn., and sequestration at surfaces, requires the paradigm of sol. redox shuttles in geochem. to be adjusted to include binding and modification of surfaces. Moreover, the known ability of isoalloxazine rings to act as metal chelators, along with their electron shuttling capacity, suggests that extracellular respiration of minerals by Shewanella is more complex than originally conceived.
- 45Okamoto, A.; Hashimoto, K.; Nealson, K. H.; Nakamura, R. Rate Enhancement of Bacterial Extracellular Electron Transport Involves Bound flavin Semiquinones. Proc. Natl. Acad. Sci. U. S. A. 2013, 110 (19), 7856– 7861, DOI: 10.1073/pnas.122082311045https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXptFGrtb8%253D&md5=a666542718effb789080d7bb0427c0b6Rate enhancement of bacterial extracellular electron transport involves bound flavin semiquinonesOkamoto, Akihiro; Hashimoto, Kazuhito; Nealson, Kenneth H.; Nakamura, RyuheiProceedings of the National Academy of Sciences of the United States of America (2013), 110 (19), 7856-7861, S7856/1-S7856/6CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Extracellular redox-active compds., flavins and other quinones, have been hypothesized to play a major role in the delivery of electrons from cellular metabolic systems to extracellular insol. substrates by a diffusion-based shuttling two-electron-transfer mechanism. Here, the authors show that flavin mols. secreted by Shewanella oneidensis MR-1 enhance the ability of its outer membrane c-type cytochromes (OM c-Cyts) to transport electrons as redox cofactors, but not free-form flavins. Whole-cell differential pulse voltammetry revealed that the redox potential of flavin was reversibly shifted more than 100 mV in a pos. direction, in good agreement with increasing microbial current generation. Importantly, this flavin/OM c-Cyts interaction was found to facilitate a one-electron redox reaction via a semiquinone, resulting in a 103- to 105-fold faster reaction rate than that of free flavin. These results are not consistent with previously proposed redox-shuttling mechanisms but suggest that the flavin/OM c-Cyts interaction regulates the extent of extracellular electron transport coupled with intracellular metabolic activity.
- 46Carmona-Martinez, A. A.; Harnisch, F.; Fitzgerald, L. A.; Biffinger, J. C.; Ringeisen, B. R.; Schröder, U. Cyclic Voltammetric Analysis of the Electron Transfer of Shewanella oneidensis MR-1 and Nanofilament and Cytochrome Knock-out Mutants. bioelectrochemistry 2011, 81 (2), 74– 80, DOI: 10.1016/j.bioelechem.2011.02.00646https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXmsVynt7c%253D&md5=b071994b1d58105ad8ab27e948ac600eCyclic voltammetric analysis of the electron transfer of Shewanella oneidensis MR-1 and nanofilament and cytochrome knock-out mutantsCarmona-Martinez, Alessandro A.; Harnisch, Falk; Fitzgerald, Lisa A.; Biffinger, Justin C.; Ringeisen, Bradley R.; Schroeder, UweBioelectrochemistry (2011), 81 (2), 74-80CODEN: BIOEFK; ISSN:1567-5394. (Elsevier B.V.)Shewanella is frequently used as a model microorganism for microbial bioelectrochem. systems. In this study, we used cyclic voltammetry (CV) to investigate extracellular electron transfer mechanisms from S. oneidensis MR-1 (WT) and five deletion mutants: membrane bound cytochrome (ΔmtrC/ΔomcA), transmembrane pili (ΔpilM-Q, ΔmshH-Q, and ΔpilM-Q/ΔmshH-Q) and flagella (Δflg). We demonstrate that the formal potentials of mediated and direct electron transfer sites of the derived biofilms can be gained from CVs of the resp. biofilms recorded at bioelectrocatlytic (i.e. turnover) and lactate depleted (i.e. non-turnover) conditions. As the biofilms possess only a limited bioelectrocatalytic activity, an advanced data processing procedure, using the open-source software SOAS, was applied. The obtained results indicate that S. oneidensis mutants used in this study are able to bypass hindered direct electron transfer by alternative redox proteins as well as self-mediated pathways.
- 47Wang, S.; Zhang, J.; Gharbi, O.; Vivier, V.; Gao, M.; Orazem, M. E. Electrochemical Impedance Spectroscopy. Nat. Rev. Methods Primer 2021, 1 (1), 1– 21, DOI: 10.1038/s43586-021-00039-wThere is no corresponding record for this reference.
- 48Menzinger, M.; Wolfgang, R. The Meaning and Use of the Arrhenius Activation Energy. Angew. Chem., Int. Ed. Engl. 1969, 8 (6), 438– 444, DOI: 10.1002/anie.19690438148https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaF1MXksVaks7o%253D&md5=2369482a85bbf9d9a85f442dc1700e4bMeaning and use of the Arrhenius activation energyMenzinger, Michael A.; Wolfgang, RichardAngewandte Chemie, International Edition in English (1969), 8 (6), 438-44CODEN: ACIEAY; ISSN:0570-0833.The nature of the Arrhenius activation energy and frequency factor is reexamd. in terms of data now available on the microscopic aspects of collisional reactions. The conceptual meaning of the activation energy is discussed, and the temp. dependence of this quantity and its relation to the threshold energy are developed for a no. of representative forms of the energy dependence of the reaction cross section. The uses and limitations of the activation energy as a means of evaluating thresholds, excitation functions, and the presence of tunneling processes are discussed.
- 49Angulo, A.; van der Linde, P.; Gardeniers, H.; Modestino, M.; Fernández Rivas, D. Influence of Bubbles on the Energy Conversion Efficiency of Electrochemical Reactors. Joule 2020, 4 (3), 555– 579, DOI: 10.1016/j.joule.2020.01.00549https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXlvVOmsLc%253D&md5=6c586c28ba85d5d4d737850510270532Influence of bubbles on the energy conversion efficiency of electrochemical reactorsAngulo, Andrea; van der Linde, Peter; Gardeniers, Han; Modestino, Miguel; Fernandez Rivas, DavidJoule (2020), 4 (3), 555-579CODEN: JOULBR; ISSN:2542-4351. (Cell Press)A review. Bubbles are known to influence energy and mass transfer in gas-evolving electrodes. However, we lack a detailed understanding on the intricate dependencies between bubble evolution processes and electrochem. phenomena. This review discusses our current knowledge on the effects of bubbles on electrochem. systems with the aim to identify opportunities and motivate future research in this area. We first provide a base background on the physics of bubble evolution as it relates to electrochem. processes. Then we outline how bubbles affect energy efficiency of electrode processes, detailing the bubble-induced impacts on activation, ohmic, and concn. overpotentials. Lastly, we describe different strategies to mitigate losses and how to exploit bubbles to enhance electrochem. reactions.
- 50Nevin, K. P.; Hensley, S. A.; Franks, A. E.; Summers, Z. M.; Ou, J.; Woodard, T. L.; Snoeyenbos-West, O. L.; Lovley, D. R. Electrosynthesis of Organic Compounds from Carbon Dioxide Is Catalyzed by a Diversity of Acetogenic Microorganisms. Appl. Environ. Microbiol. 2011, 77 (9), 2882– 2886, DOI: 10.1128/AEM.02642-1050https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtVeju7bF&md5=4293c1828d5f7e8dc43a9165ae02f247Electrosynthesis of organic compounds from carbon dioxide is catalyzed by a diversity of acetogenic microorganismsNevin, Kelly P.; Hensley, Sarah A.; Franks, Ashley E.; Summers, Zarath M.; Ou, Jianhong; Woodard, Trevor L.; Snoeyenbos-West, Oona L.; Lovley, Derek R.Applied and Environmental Microbiology (2011), 77 (9), 2882-2886CODEN: AEMIDF; ISSN:0099-2240. (American Society for Microbiology)Microbial electrosynthesis, a process in which microorganisms use electrons derived from electrodes to reduce carbon dioxide to multicarbon, extracellular org. compds., is a potential strategy for capturing elec. energy in carbon-carbon bonds of readily stored and easily distributed products, such as transportation fuels. To date, only one organism, the acetogen Sporomusa ovata, has been shown to be capable of electrosynthesis. The purpose of this study was to det. if a wider range of microorganisms is capable of this process. Several other acetogenic bacteria, including two other Sporomusa species, Clostridium ljungdahlii, Clostridium aceticum, and Moorella thermoacetica, consumed current with the prodn. of org. acids. In general acetate was the primary product, but 2-oxobutyrate and formate also were formed, with 2-oxobutyrate being the predominant identified product of electrosynthesis by C. aceticum. S. sphaeroides, C. ljungdahlii, and M. thermoacetica had high (>80%) efficiencies of electrons consumed and recovered in identified products. The acetogen Acetobacterium woodii was unable to consume current. These results expand the known range of microorganisms capable of electrosynthesis, providing multiple options for the further optimization of this process.
- 51Liu, X.; Huang, L.; Rensing, C.; Ye, J.; Nealson, K. H.; Zhou, S. Syntrophic Interspecies Electron Transfer Drives Carbon Fixation and Growth by Rhodopseudomonas Palustris under Dark, Anoxic Conditions. Sci. Adv. 2021, 7 (27), eabh1852 DOI: 10.1126/sciadv.abh1852There is no corresponding record for this reference.
- 52Yang, G.; Huang, L.; You, L.; Zhuang, L.; Zhou, S. Electrochemical and Spectroscopic Insights into the Mechanisms of Bidirectional Microbe-Electrode Electron Transfer in Geobacter Soli Biofilms. Electrochem. Commun. 2017, 77, 93– 97, DOI: 10.1016/j.elecom.2017.03.00452https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXktVKlsLs%253D&md5=2ae0c667d9282871d734d584cb865b1bElectrochemical and spectroscopic insights into the mechanisms of bidirectional microbe-electrode electron transfer in Geobacter soli biofilmsYang, Guiqin; Huang, Lingyan; You, Lexing; Zhuang, Li; Zhou, ShunguiElectrochemistry Communications (2017), 77 (), 93-97CODEN: ECCMF9; ISSN:1388-2481. (Elsevier B.V.)Few electroactive bacteria have shown the capacity of exchanging electrons with electrode in both directions, and the mechanisms of such bidirectional electron transfer remain uncertain hitherto. In this study, we demonstrate that Geobacter soli biofilms could directly donate electrons to and accept electrons from graphite electrode. Under anodic conditions, G. soli oxidizes acetate to generate current, and under cathodic conditions, nitrate is reduced by a truncated denitrification pathway with nitrous oxide as end product. Cyclic voltammetry, differential pulse voltammetry and electrochem. in situ FTIR spectra demonstrate that distinct external membrane redox systems exist in the anode and cathode biofilms, which supports the conclusion that G. soli uses different electron transfer conduits for bidirectional electron transfer. These results expand the horizon of bidirectional electron transfer mechanisms, meanwhile this study represents a first report that Geobacter species might utilize electrode as electron donor for incomplete denitrification.
- 53Yu, Q.; Mao, H.; Yang, B.; Zhu, Y.; Sun, C.; Zhao, Z.; Li, Y.; Zhang, Y. Electro-Polarization of Protein-like Substances Accelerates Trans-Cell-Wall Electron Transfer in Microbial Extracellular Respiration. iScience 2023, 26 (2), 106065 DOI: 10.1016/j.isci.2023.106065There is no corresponding record for this reference.
- 54Yu, Q.; Zhang, Y. Fouling-Resistant Biofilter of an Anaerobic Electrochemical Membrane Reactor. Nat. Commun. 2019, 10 (1), 4860, DOI: 10.1038/s41467-019-12838-7There is no corresponding record for this reference.
- 55Dubois, V.; Umari, P.; Pasquarello, A. Dielectric Susceptibility of Dipolar Molecular Liquids by Ab Initio Molecular Dynamics: Application to Liquid HCl. Chem. Phys. Lett. 2004, 390 (1), 193– 198, DOI: 10.1016/j.cplett.2004.04.021There is no corresponding record for this reference.
- 56Chen, L.; Li, X.; Xie, Y.; Liu, N.; Qin, X.; Chen, X.; Bu, Y. Modulation of Proton-Coupled Electron Transfer Reactions in Lysine-Containing Alpha-Helixes: Alpha-Helixes Promoting Long-Range Electron Transfer. Phys. Chem. Chem. Phys. 2022, 24 (23), 14592– 14602, DOI: 10.1039/D2CP00666AThere is no corresponding record for this reference.
- 57Lauz, M.; Eckhardt, S.; Fromm, K. M.; Giese, B. The Influence of Dipole Moments on the Mechanism of Electron Transfer through Helical Peptides.. Phys. Chem. Chem. Phys. 2012, 14 (40), 13785– 13788, DOI: 10.1039/c2cp41159hThere is no corresponding record for this reference.
- 58Sawicka, A.; Skurski, P.; Hudgins, R. R.; Simons, J. Model Calculations Relevant to Disulfide Bond Cleavage via Electron Capture Influenced by Positively Charged Groups. J. Phys. Chem. B 2003, 107 (48), 13505– 13511, DOI: 10.1021/jp035675d58https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXovVClurw%253D&md5=c1000f8c129f9bcd0cd8881c33bd73faModel Calculations Relevant to Disulfide Bond Cleavage via Electron Capture Influenced by Positively Charged GroupsSawicka, Agnieszka; Skurski, Piotr; Hudgins, Robert R.; Simons, JackJournal of Physical Chemistry B (2003), 107 (48), 13505-13511CODEN: JPCBFK; ISSN:1520-6106. (American Chemical Society)Ab initio electronic structure calcns. are used to explore the effect of nonneighboring pos. charged groups on the ability of low-energy (<1 eV) electrons to directly attach to S-S σ bonds in disulfides to effect bond cleavage. It is shown that, although direct vertical attachment to the σ* orbital of an S-S σ bond is endothermic, the stabilizing Coulomb potential produced in the region of the S-S bond by one or more distant pos. groups can render the S-S σ* anion state electronically stable. This stabilization, in turn, can make near vertical electron attachment exothermic. The focus of these model studies is to elucidate a proposed mechanism for bond rupture that may, in addn. to other mechanisms, be operative in electron capture dissocn. (ECD) expts. The importance of these findings lies in the fact that a more complete understanding of how ECD takes place will allow workers to better interpret ECD fragmentation patterns obsd. in mass spectrometric studies of proteins and polypeptides.
- 59Okamoto, A.; Tokunou, Y.; Kalathil, S.; Hashimoto, K. Proton Transport in the Outer-Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron Transport. Angew. Chem., Int. Ed. 2017, 56 (31), 9082– 9086, DOI: 10.1002/anie.20170424159https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtV2gs7%252FJ&md5=4bbeb45d3d6b6037f4af828787f67177Proton Transport in the Outer-Membrane Flavocytochrome Complex Limits the Rate of Extracellular Electron TransportOkamoto, Akihiro; Tokunou, Yoshihide; Kalathil, Shafeer; Hashimoto, KazuhitoAngewandte Chemie, International Edition (2017), 56 (31), 9082-9086CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)The microbial transfer of electrons to extracellularly located solid compds., termed extracellular electron transport (EET), is crit. for microbial electrode catalysis. Although the components of the EET pathway in the outer membrane (OM) have been identified, the role of electron/cation coupling in EET kinetics is poorly understood. We studied the dynamics of proton transport assocd. with EET in an OM flavocytochrome complex in Shewanella oneidensis MR-1. Using a whole-cell electrochem. assay, a significant kinetic isotope effect (KIE) was obsd. following the addn. of deuterated water (D2O). The removal of a flavin cofactor or key components of the OM flavocytochrome complex significantly increased the KIE in the presence of D2O to values that were significantly larger than those reported for proton channels and ATP synthase, thus indicating that proton transport by OM flavocytochrome complexes limits the rate of EET.
- 60Kumar, A.; Hsu, L. H. H.; Kavanagh, P.; Barrière, F.; Lens, P. N. L.; Lapinsonnière, L.; Lienhard V, J. H.; Schröder, U.; Jiang, X.; Leech, D. The Ins and Outs of Microorganism–Electrode Electron Transfer Reactions. Nat. Rev. Chem. 2017, 1 (3), 1– 13, DOI: 10.1038/s41570-017-0024There is no corresponding record for this reference.
- 61Ren, Y.; Yu, C.; Tan, X.; Huang, H.; Wei, Q.; Qiu, J. Strategies to Suppress Hydrogen Evolution for Highly Selective Electrocatalytic Nitrogen Reduction: Challenges and Perspectives. Energy Environ. Sci. 2021, 14 (3), 1176– 1193, DOI: 10.1039/D0EE03596C61https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhsVGnt7Y%253D&md5=1883f9ec644f0a417a4e9a9f1a0ca591Strategies to suppress hydrogen evolution for highly selective electrocatalytic nitrogen reduction: challenges and perspectivesRen, Yongwen; Yu, Chang; Tan, Xinyi; Huang, Hongling; Wei, Qianbing; Qiu, JieshanEnergy & Environmental Science (2021), 14 (3), 1176-1193CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)A review. Ammonia, as a significant chem. for fertilizer prodn. and also a promising energy carrier, is mainly produced through the traditional energy-intensive Haber-Bosch process. Recently, the electrocatalytic N2 redn. reaction (NRR) for ammonia synthesis has received tremendous attention with the merits of energy saving and environmental friendliness. To date, the development of the NRR process is primarily hindered by the competing hydrogen evolution reaction (HER), whereas the corresponding strategies for inhibiting this undesired side reaction to achieve high NRR selectivity are still quite limited. Furthermore, for such a complex reaction involving three gas-liq.-solid phases and proton/electron transfer, it is also rather meaningful to decouple and summarize the current strategies for suppressing H2 evolution in terms of NRR mechanisms, kinetics, thermodn., and electrocatalyst design in detail. Herein, on the basis of the NRR mechanisms, we systematically summarize the recent strategies to inhibit the HER for a highly selective electrocatalytic NRR, focusing on limiting the proton- and electron-transfer kinetics, shifting the chem. equil., and designing the electrocatalysts. Addnl., insights into boosting the NRR selectivity and efficiency for practical applications are also presented in detail with regard to the detn. of ammonia, the activation of the N2 mol., the regulation of the gas-liq.-solid three-phase interface, the coupled NRR with value-added oxidn. reactions, and the development of flow cell reactors.
- 62van der Ham, C. J. M.; Koper, M. T. M.; Hetterscheid, D. G. H. Challenges in Reduction of Dinitrogen by Proton and Electron Transfer. Chem. Soc. Rev. 2014, 43 (15), 5183– 5191, DOI: 10.1039/C4CS00085D62https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFWhsL3E&md5=7a634f6a6cdb86ca035e350c604b4007Challenges in reduction of dinitrogen by proton and electron transfervan der Ham, Cornelis J. M.; Koper, Marc T. M.; Hetterscheid, Dennis G. H.Chemical Society Reviews (2014), 43 (15), 5183-5191CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)A review. Ammonia is an important nutrient for the growth of plants. In industry, ammonia is produced by the energy expensive Haber-Bosch process where dihydrogen and dinitrogen form ammonia at a very high pressure and temp. In principle one could also reduce dinitrogen upon addn. of protons and electrons similar to the mechanism of ammonia prodn. by nitrogenases. Recently, major breakthroughs have taken place in our understanding of biol. fixation of dinitrogen, of mol. model systems that can reduce dinitrogen, and in the electrochem. redn. of dinitrogen at heterogeneous surfaces. Yet for efficient redn. of dinitrogen with protons and electrons major hurdles still have to be overcome. The authors give an overview of the different catalytic systems, highlight the recent breakthroughs, pinpoint common grounds and discuss the bottlenecks and challenges in catalytic redn. of dinitrogen.
- 63Ram, M.; Child, M.; Aghahosseini, A.; Bogdanov, D.; Lohrmann, A.; Breyer, C. A Comparative Analysis of Electricity Generation Costs from Renewable, Fossil Fuel and Nuclear Sources in G20 Countries for the Period 2015–2030. J. Clean. Prod. 2018, 199, 687– 704, DOI: 10.1016/j.jclepro.2018.07.159There is no corresponding record for this reference.
- 64De Luna, P.; Hahn, C.; Higgins, D.; Jaffer, S. A.; Jaramillo, T. F.; Sargent, E. H. What Would It Take for Renewably Powered Electrosynthesis to Displace Petrochemical Processes?. Science 2019, 364 (6438), eaav3506 DOI: 10.1126/science.aav3506There is no corresponding record for this reference.
- 65Sakimoto, K. K.; Wong, A. B.; Yang, P. Self-Photosensitization of Nonphotosynthetic Bacteria for Solar-to-Chemical Production. Science 2016, 351 (6268), 74– 77, DOI: 10.1126/science.aad331765https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitV2nsbnI&md5=40593834d3255adc14e8c439838b1acbSelf-photosensitization of nonphotosynthetic bacteria for solar-to-chemical productionSakimoto, Kelsey K.; Wong, Andrew Barnabas; Yang, PeidongScience (Washington, DC, United States) (2016), 351 (6268), 74-77CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Improving natural photosynthesis can enable the sustainable prodn. of chems. However, neither purely artificial nor purely biol. approaches seem poised to realize the potential of solar-to-chem. synthesis. We developed a hybrid approach, whereby we combined the highly efficient light harvesting of inorg. semiconductors with the high specificity, low cost, and self-replication and -repair of biocatalysts. We induced the self-photosensitization of a nonphotosynthetic bacterium, Moorella thermoacetica, with cadmium sulfide nanoparticles, enabling the photosynthesis of acetic acid from carbon dioxide. Biol. pptd. cadmium sulfide nanoparticles served as the light harvester to sustain cellular metab. This self-augmented biol. system selectively produced acetic acid continuously over several days of light-dark cycles at relatively high quantum yields, demonstrating a self-replicating route toward solar-to-chem. carbon dioxide redn.
- 66Deng, X.; Dohmae, N.; Kaksonen, A. H.; Okamoto, A. Biogenic Iron Sulfide Nanoparticles to Enable Extracellular Electron Uptake in Sulfate-Reducing Bacteria. Angew. Chem. 2020, 132 (15), 6051– 6055, DOI: 10.1002/ange.201915196There is no corresponding record for this reference.
Supporting Information
Supporting Information
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.est.3c10897.
Photographs of biosynthesized FeS in wild-type and mutant strains; Fe(II) concentration, UV–vis-NIR absorption spectra, and electrochemical characteristics (CV, capacitance, Nyquist plots, and the values of Rs and Rct) in the optimizing biosynthesized-FeS NPs experiments; CLSM images of S. oneidensis and S. oneidensis@FeS biofilm; SEM and EDS mapping images of S. oneidensis and S. oneidensis@FeS; HAADF-STEM and EDS mapping images of the sliced mutant strains-FeS; TOC concentration in S. oneidensis, S. oneidensis@FeS, mutant strains, and mutant strains-FeS systems; schematic diagram and the composition of electrolyte solution in MES system (Figures S1–S11 and Table S1) (PDF)
Terms & Conditions
Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.
