51
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SAITO J, HASHIMOTO K, OKAMOTO A. Nanoscale Secondary Ion Mass Spectrometry Analysis of Individual Bacterial Cells Reveals Feedback from Extracellular Electron Transport to Upstream Reactions. ELECTROCHEMISTRY 2017. [DOI: 10.5796/electrochemistry.85.444] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Junki SAITO
- Department of Applied Chemistry, School of Engineering, The University of Tokyo
| | - Kazuhito HASHIMOTO
- Global Research Center for Environment and Energy based on Nanomaterials Science, National Institute for Materials Science
| | - Akihiro OKAMOTO
- Global Research Center for Environment and Energy based on Nanomaterials Science, National Institute for Materials Science
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52
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Extracellular Electron Transfer and Biosensors. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2017; 167:15-38. [PMID: 29071406 DOI: 10.1007/10_2017_34] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This chapter summarizes in the beginning our current understanding of extracellular electron transport processes in organisms belonging to the genera Shewanella and Geobacter. Organisms belonging to these genera developed strategies to transport respiratory electrons to the cell surface that are defined by modules of which some seem to be rather unique for one or the other genus while others are similar. We use this overview regarding our current knowledge of extracellular electron transfer to explain the physiological interaction of microorganisms in direct interspecies electron transfer, a process in which one organism basically comprises the electron acceptor for another microbe and that depends also on extended electron transport chains. This analysis of mechanisms for the transport of respiratory electrons to insoluble electron acceptors ends with an overview of questions that remain so far unanswered. Moreover, we use the description of the biochemistry of extracellular electron transport to explain the fundamentals of biosensors based on this process and give an overview regarding their status of development and applicability. Graphical Abstract.
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53
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Sugnaux M, Happe M, Cachelin CP, Gloriod O, Huguenin G, Blatter M, Fischer F. Two stage bioethanol refining with multi litre stacked microbial fuel cell and microbial electrolysis cell. BIORESOURCE TECHNOLOGY 2016; 221:61-69. [PMID: 27639225 DOI: 10.1016/j.biortech.2016.09.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/02/2016] [Accepted: 09/03/2016] [Indexed: 06/06/2023]
Abstract
Ethanol, electricity, hydrogen and methane were produced in a two stage bioethanol refinery setup based on a 10L microbial fuel cell (MFC) and a 33L microbial electrolysis cell (MEC). The MFC was a triple stack for ethanol and electricity co-generation. The stack configuration produced more ethanol with faster glucose consumption the higher the stack potential. Under electrolytic conditions ethanol productivity outperformed standard conditions and reached 96.3% of the theoretically best case. At lower external loads currents and working potentials oscillated in a self-synchronized manner over all three MFC units in the stack. In the second refining stage, fermentation waste was converted into methane, using the scale up MEC stack. The bioelectric methanisation reached 91% efficiency at room temperature with an applied voltage of 1.5V using nickel cathodes. The two stage bioethanol refining process employing bioelectrochemical reactors produces more energy vectors than is possible with today's ethanol distilleries.
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Affiliation(s)
- Marc Sugnaux
- Institute of Life Technologies, HES-SO Valais, University of Applied Sciences and Arts Western Switzerland Valais, Route du Rawyl 64, 1950 Sion, Switzerland
| | - Manuel Happe
- Institute of Life Technologies, HES-SO Valais, University of Applied Sciences and Arts Western Switzerland Valais, Route du Rawyl 64, 1950 Sion, Switzerland
| | - Christian Pierre Cachelin
- Systems Engineering, HES-SO Valais, University of Applied Sciences and Arts Western Switzerland, Route du Rawyl 47, 1950 Sion, Switzerland
| | - Olivier Gloriod
- Systèmes Informatiques Embarqués, Haute École Arc, University of Applied Sciences and Arts Western Switzerland, Rue de la Serre 7, 2610 St-Imier, Switzerland
| | - Gérald Huguenin
- Systèmes Informatiques Embarqués, Haute École Arc, University of Applied Sciences and Arts Western Switzerland, Rue de la Serre 7, 2610 St-Imier, Switzerland
| | - Maxime Blatter
- Institute of Life Technologies, HES-SO Valais, University of Applied Sciences and Arts Western Switzerland Valais, Route du Rawyl 64, 1950 Sion, Switzerland
| | - Fabian Fischer
- Institute of Life Technologies, HES-SO Valais, University of Applied Sciences and Arts Western Switzerland Valais, Route du Rawyl 64, 1950 Sion, Switzerland.
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54
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Ding M, Shiu HY, Li SL, Lee CK, Wang G, Wu H, Weiss NO, Young TD, Weiss PS, Wong GCL, Nealson KH, Huang Y, Duan X. Nanoelectronic Investigation Reveals the Electrochemical Basis of Electrical Conductivity in Shewanella and Geobacter. ACS NANO 2016; 10:9919-9926. [PMID: 27787972 DOI: 10.1021/acsnano.6b03655] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The electrical conductivity measured in Shewanella and Geobacter spp. is an intriguing physical property that is the fundamental basis for possible extracellular electron transport (EET) pathways. There is considerable debate regarding the origins of the electrical conductivity reported in these microbial cellular structures, which is essential for deciphering the EET mechanism. Here, we report systematic on-chip nanoelectronic investigations of both Shewanella and Geobacter spp. under physiological conditions to elucidate the complex basis of electrical conductivity of both individual microbial cells and biofilms. Concurrent electrical and electrochemical measurements of living Shewanella at both few-cell and the biofilm levels indicate that the apparent electrical conductivity can be traced to electrochemical-based electron transfer at the cell/electrode interface. We further show that similar results and conclusions apply to the Geobacter spp. Taken together, our study offers important insights into previously proposed physical models regarding microbial conductivities as well as EET pathways for Shewanella and Geobacter spp.
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Affiliation(s)
| | | | - Shiue-Lin Li
- Department of Earth Sciences and Biological Sciences, University of Southern California , Los Angeles, California 90089, United States
| | | | | | | | | | | | | | | | - Kenneth H Nealson
- Department of Earth Sciences and Biological Sciences, University of Southern California , Los Angeles, California 90089, United States
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55
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Lee CK, Kim AJ, Santos GS, Lai PY, Lee SY, Qiao DF, Anda JD, Young TD, Chen Y, Rowe AR, Nealson KH, Weiss PS, Wong GCL. Evolution of Cell Size Homeostasis and Growth Rate Diversity during Initial Surface Colonization of Shewanella oneidensis. ACS NANO 2016; 10:9183-9192. [PMID: 27571459 DOI: 10.1021/acsnano.6b05123] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Cell size control and homeostasis are fundamental features of bacterial metabolism. Recent work suggests that cells add a constant size between birth and division ("adder" model). However, it is not known how cell size homeostasis is influenced by the existence of heterogeneous microenvironments, such as those during biofilm formation. Shewanella oneidensis MR-1 can use diverse energy sources on a range of surfaces via extracellular electron transport (EET), which can impact growth, metabolism, and size diversity. Here, we track bacterial surface communities at single-cell resolution to show that not only do bacterial motility appendages influence the transition from two- to three-dimensional biofilm growth and control postdivisional cell fates, they strongly impact cell size homeostasis. For every generation, we find that the average growth rate for cells that stay on the surface and continue to divide (nondetaching population) and that for cells that detach before their next division (detaching population) are roughly constant. However, the growth rate distribution is narrow for the nondetaching population, but broad for the detaching population in each generation. Interestingly, the appendage deletion mutants (ΔpilA, ΔmshA-D, Δflg) have significantly broader growth rate distributions than that of the wild type for both detaching and nondetaching populations, which suggests that Shewanella appendages are important for sensing and integrating environmental inputs that contribute to size homeostasis. Moreover, our results suggest multiplexing of appendages for sensing and motility functions contributes to cell size dysregulation. These results can potentially provide a framework for generating metabolic diversity in S. oneidensis populations to optimize EET in heterogeneous environments.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Annette R Rowe
- Department of Earth Sciences & Biological Sciences, University of Southern California , Los Angeles, California 90089, United States
| | - Kenneth H Nealson
- Department of Earth Sciences & Biological Sciences, University of Southern California , Los Angeles, California 90089, United States
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56
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Flavin as an Indicator of the Rate-Limiting Factor for Microbial Current Production in Shewanella oneidensis MR-1. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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57
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Jensen HM, TerAvest MA, Kokish MG, Ajo-Franklin CM. CymA and Exogenous Flavins Improve Extracellular Electron Transfer and Couple It to Cell Growth in Mtr-Expressing Escherichia coli. ACS Synth Biol 2016; 5:679-88. [PMID: 27000939 DOI: 10.1021/acssynbio.5b00279] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Introducing extracellular electron transfer pathways into heterologous organisms offers the opportunity to explore fundamental biogeochemical processes and to biologically alter redox states of exogenous metals for various applications. While expression of the MtrCAB electron nanoconduit from Shewanella oneidensis MR-1 permits extracellular electron transfer in Escherichia coli, the low electron flux and absence of growth in these cells limits their practicality for such applications. Here we investigate how the rate of electron transfer to extracellular Fe(III) and cell survival in engineered E. coli are affected by mimicking different features of the S. oneidensis pathway: the number of electron nanoconduits, the link between the quinol pool and MtrA, and the presence of flavin-dependent electron transfer. While increasing the number of pathways does not significantly improve the extracellular electron transfer rate or cell survival, using the native inner membrane component, CymA, significantly improves the reduction rate of extracellular acceptors and increases cell viability. Strikingly, introducing both CymA and riboflavin to Mtr-expressing E. coli also allowed these cells to couple metal reduction to growth, which is the first time an increase in biomass of an engineered E. coli has been observed under Fe2O3 (s) reducing conditions. Overall, this work provides engineered E. coli strains for modulating extracellular metal reduction and elucidates critical factors for engineering extracellular electron transfer in heterologous organisms.
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Affiliation(s)
- Heather M. Jensen
- Physical
Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Michaela A. TerAvest
- California
Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, United States
| | - Mark G. Kokish
- Materials
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Caroline M. Ajo-Franklin
- Physical
Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Materials
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Synthetic Biology Institute, Berkeley, California 94720, United States
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58
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59
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Hong G, Pachter R. Bound Flavin-Cytochrome Model of Extracellular Electron Transfer in Shewanella oneidensis: Analysis by Free Energy Molecular Dynamics Simulations. J Phys Chem B 2016; 120:5617-24. [PMID: 27266856 DOI: 10.1021/acs.jpcb.6b03851] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Flavins are known to enhance extracellular electron transfer (EET) in Shewanella oneidensis MR-1 bacteria, which reduce electron acceptors through outer-membrane (OM) cytochromes c. Free-shuttle and bound-redox cofactor mechanisms were proposed to explain this enhancement, but recent electrochemical reports favor a flavin-bound model, proposing two one-electron reductions of flavin, namely, oxidized (Ox) to semiquinone (Sq) and semiquinone to hydroquinone (Hq), at anodic and cathodic conditions, respectively. In this work, to provide a mechanistic understanding of riboflavin (RF) binding at the multiheme OM cytochrome OmcA, we explored binding configurations at hemes 2, 5, 7, and 10. Subsequently, on the basis of molecular dynamics (MD) simulations, binding free energies and redox potential shifts upon RF binding for the Ox/Sq and Sq/Hq reductions were analyzed. Our results demonstrated an upshift in the Ox/Sq and a downshift in the Sq/Hq redox potentials, consistent with a bound RF-OmcA model. Furthermore, binding free energy MD simulations indicated an RF binding preference at heme 7. MD simulations of the OmcA-MtrC complex interfacing at hemes 5 revealed a small interprotein redox potential difference with an electron transfer rate of 10(7)-10(8)/s.
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Affiliation(s)
- Gongyi Hong
- Air Force Research Laboratory , Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, United States
| | - Ruth Pachter
- Air Force Research Laboratory , Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, United States
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60
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Nakanihi S, Okamoto A, Hashimoto K. ELECTROCHEMISTRY 2016; 84:93-98. [DOI: 10.5796/electrochemistry.84.93] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] Open
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61
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Zhang X, Liu H, Wang J, Ren G, Xie B, Liu H, Zhu Y, Jiang L. Facilitated extracellular electron transfer of Shewanella loihica PV-4 by antimony-doped tin oxide nanoparticles as active microelectrodes. NANOSCALE 2015; 7:18763-18769. [PMID: 26505239 DOI: 10.1039/c5nr04765j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Dissimilatory metal reducing bacteria are capable of extracellular electron transfer (EET) to insoluble metal oxides as external electron acceptors for their anaerobic respiration, which is recognized as an important energy-conversion process in natural and engineered environments, such as in mineral cycling, bioremediation, and microbial fuel/electrolysis cells. However, the low EET efficiency remains one of the major bottlenecks for its practical application. We report firstly that the microbial current generated by Shewanella loihica PV-4 (S. loihica PV-4) could be greatly improved that is up to ca. 115 fold, by adding antimony-doped tin oxide (ATO) nanoparticles in the electrochemical reactor. The results demonstrate that the biocompatible, electrically conductive ATO nanoparticles acted as active microelectrodes could facilitate the formation of a cells/ATO composite biofilm and the reduction of the outer membrane c-type cytochromes (OM c-Cyts) that are beneficial for the electron transfer from cells to electrode. Meanwhile, a synergistic effect between the participation of OM c-Cyts and the accelerated EET mediated by cell-secreted flavins may play an important role for the enhanced current generation in the presence of ATO nanoparticles. Moreover, it is worth noting that the TCA cycle in S. loihica PV-4 cells is activated by adding ATO nanoparticles, even if the potential is poised at +0.2 V, thereby also improving the EET process. The results presented here may provide a simple and effective strategy to boost the EET of S. loihica PV-4 cells, which is conducive to providing potential applications in bioelectrochemical systems.
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Affiliation(s)
- Xiaojian Zhang
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, Beijing Key Laboratory of Bio-inspired Energy Materials and Devices, School of Chemistry and Environment, Beihang University, Beijing 100191, PR China.
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62
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Yang Y, Wu Y, Hu Y, Cao Y, Poh CL, Cao B, Song H. Engineering Electrode-Attached Microbial Consortia for High-Performance Xylose-Fed Microbial Fuel Cell. ACS Catal 2015. [DOI: 10.1021/acscatal.5b01733] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Yun Yang
- School
of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457, Singapore
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Yichao Wu
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
- School
of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 637798, Singapore
| | - Yidan Hu
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Yingxiu Cao
- Key
Laboratory of Systems Bioengineering (Ministry of Education), SynBio
Research Platform, Collaborative Innovation Center of Chemical Science
and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Chueh Loo Poh
- School
of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457, Singapore
| | - Bin Cao
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
- School
of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 637798, Singapore
| | - Hao Song
- Key
Laboratory of Systems Bioengineering (Ministry of Education), SynBio
Research Platform, Collaborative Innovation Center of Chemical Science
and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
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63
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Yang Y, Ding Y, Hu Y, Cao B, Rice SA, Kjelleberg S, Song H. Enhancing Bidirectional Electron Transfer of Shewanella oneidensis by a Synthetic Flavin Pathway. ACS Synth Biol 2015; 4:815-23. [PMID: 25621739 DOI: 10.1021/sb500331x] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Flavins regulate the rate and direction of extracellular electron transfer (EET) in Shewanella oneidensis. However, low concentration of endogenously secreted flavins by the wild-type S. oneidensis MR-1 limits its EET efficiency in bioelectrochemical systems (BES). Herein, a synthetic flavin biosynthesis pathway from Bacillus subtilis was heterologously expressed in S. oneidensis MR-1, resulting in ∼25.7 times' increase in secreted flavin concentration. This synthetic flavin module enabled enhanced bidirectional EET rate of MR-1, in which its maximum power output in microbial fuel cells increased ∼13.2 times (from 16.4 to 233.0 mW/m(2)), and the inward current increased ∼15.5 times (from 15.5 to 255.3 μA/cm(2)).
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Affiliation(s)
- Yun Yang
- School
of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Yuanzhao Ding
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Yidan Hu
- School
of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Bin Cao
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
- School
of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 637798, Singapore
| | - Scott A. Rice
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Staffan Kjelleberg
- Singapore
Centre on Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Hao Song
- Key
Laboratory of Systems Bioengineering (Ministry of Education), SynBio
Research Platform, Collaborative Innovation Center of Chemical Science
and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
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64
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Kondo K, Okamoto A, Hashimoto K, Nakamura R. Sulfur-Mediated Electron Shuttling Sustains Microbial Long-Distance Extracellular Electron Transfer with the Aid of Metallic Iron Sulfides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:7427-7434. [PMID: 26070345 DOI: 10.1021/acs.langmuir.5b01033] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In addition to serving as an energy source for microbial growth, iron sulfides are proposed to act as naturally occurring electrical wires that mediate long-distance extracellular electron transfer (EET) and bridge spatially discrete redox environments. These hypothetical EET reactions stand on the abilities of microbes to use the interfacial electrochemistry of metallic/semiconductive iron sulfides to maintain metabolisms; however, the mechanisms of these phenomena remain unexplored. To obtain insight into EET to iron sulfides, we monitored EET at the interface between Shewanella oneidensis MR-1 cells and biomineralized iron sulfides in an electrochemical cell. Respiratory current steeply increased with the concomitant formation of poorly crystalline mackinawite (FeS) minerals, indicating that S. oneidensis has the ability to exploit extracellularly formed metallic FeS for long-distance EET. Deletion of major proteins of the metal-reduction (Mtr) pathway (OmcA, MtrC, CymA, and PilD) caused only subtle effects on the EET efficiency, a finding that sharply contrasts the majority of studies that report that the Mtr pathway is indispensable for the reduction of metal oxides and electrodes. The gene expression analyses of polysulfide and thiosulfate reductase suggest the existence of a sulfur-mediated electron-shuttling mechanism by which HS(-) ions and water-soluble polysulfides (HS(n)(-), where n ≥ 2) generated in the periplasmic space deliver electrons from cellular metabolic processes to cell surface-associated FeS. The finding of this Mtr-independent pathway indicates that polysulfide reductases complement the function of outer-membrane cytochromes in EET reactions and, thus, significantly expand the number of microbial species potentially capable of long-distance EET in sulfur-rich anoxic environments.
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Affiliation(s)
- Katsuhito Kondo
- †Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Akihiro Okamoto
- †Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kazuhito Hashimoto
- †Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Ryuhei Nakamura
- ‡Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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65
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Tao L, Wang H, Xie M, Thia L, Chen WN, Wang X. Improving mediated electron transport in anodic bioelectrocatalysis. Chem Commun (Camb) 2015; 51:12170-3. [DOI: 10.1039/c5cc03188e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A microbial fuel cell loaded with bio-cocatalyst beads immobilized with recombinant riboflavin-secreting Escherichia coli shows significantly enhanced performance.
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Affiliation(s)
- Le Tao
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 62 Nanyang Avenue
- Singapore
| | - Haibo Wang
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 62 Nanyang Avenue
- Singapore
| | - Mingshi Xie
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 62 Nanyang Avenue
- Singapore
| | - Larissa Thia
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 62 Nanyang Avenue
- Singapore
| | - Wei Ning Chen
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 62 Nanyang Avenue
- Singapore
| | - Xin Wang
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 62 Nanyang Avenue
- Singapore
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66
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Semenec L, E Franks A. Delving through electrogenic biofilms: from anodes to cathodes to microbes. AIMS BIOENGINEERING 2015. [DOI: 10.3934/bioeng.2015.3.222] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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67
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Cell-secreted flavins bound to membrane cytochromes dictate electron transfer reactions to surfaces with diverse charge and pH. Sci Rep 2014; 4:5628. [PMID: 25012073 PMCID: PMC4092373 DOI: 10.1038/srep05628] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 06/18/2014] [Indexed: 11/08/2022] Open
Abstract
The variety of solid surfaces to and from which microbes can deliver electrons by extracellular electron transport (EET) processes via outer-membrane c-type cytochromes (OM c-Cyts) expands the importance of microbial respiration in natural environments and industrial applications. Here, we demonstrate that the bifurcated EET pathway of OM c-Cyts sustains the diversity of the EET surface in Shewanella oneidensis MR-1 via specific binding with cell-secreted flavin mononucleotide (FMN) and riboflavin (RF). Microbial current production and whole-cell differential pulse voltammetry revealed that RF and FMN enhance EET as bound cofactors in a similar manner. Conversely, FMN and RF were clearly differentiated in the EET enhancement by gene-deletion of OM c-Cyts and the dependency of the electrode potential and pH. These results indicate that RF and FMN have specific binding sites in OM c-Cyts and highlight the potential roles of these flavin-cytochrome complexes in controlling the rate of electron transfer to surfaces with diverse potential and pH.
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