251
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Yuan Y, Li L, Zhou S. Axial Ligation of Heme in c-Type Cytochromes of LivingShewanella oneidensis: A New Insight into Enhanced Extracellular Electron Transfer. ChemElectroChem 2015. [DOI: 10.1002/celc.201500234] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yong Yuan
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control; Guangdong Institute of Eco-Environmental and Soil Sciences; Guangzhou 510650 China
| | - Laicai Li
- College of Chemistry and Material Science; Sichuan Normal University; Chengdu 610066 China
| | - Shungui Zhou
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control; Guangdong Institute of Eco-Environmental and Soil Sciences; Guangzhou 510650 China
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252
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Breuer M, Rosso KM, Blumberger J, Butt JN. Multi-haem cytochromes in Shewanella oneidensis MR-1: structures, functions and opportunities. J R Soc Interface 2015; 12:20141117. [PMID: 25411412 DOI: 10.1098/rsif.2014.1117] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Multi-haem cytochromes are employed by a range of microorganisms to transport electrons over distances of up to tens of nanometres. Perhaps the most spectacular utilization of these proteins is in the reduction of extracellular solid substrates, including electrodes and insoluble mineral oxides of Fe(III) and Mn(III/IV), by species of Shewanella and Geobacter. However, multi-haem cytochromes are found in numerous and phylogenetically diverse prokaryotes where they participate in electron transfer and redox catalysis that contributes to biogeochemical cycling of N, S and Fe on the global scale. These properties of multi-haem cytochromes have attracted much interest and contributed to advances in bioenergy applications and bioremediation of contaminated soils. Looking forward, there are opportunities to engage multi-haem cytochromes for biological photovoltaic cells, microbial electrosynthesis and developing bespoke molecular devices. As a consequence, it is timely to review our present understanding of these proteins and we do this here with a focus on the multitude of functionally diverse multi-haem cytochromes in Shewanella oneidensis MR-1. We draw on findings from experimental and computational approaches which ideally complement each other in the study of these systems: computational methods can interpret experimentally determined properties in terms of molecular structure to cast light on the relation between structure and function. We show how this synergy has contributed to our understanding of multi-haem cytochromes and can be expected to continue to do so for greater insight into natural processes and their informed exploitation in biotechnologies.
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Affiliation(s)
- Marian Breuer
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Kevin M Rosso
- Pacific Northwest National Laboratory, Richland, WA, USA
| | - Jochen Blumberger
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Julea N Butt
- School of Biological Sciences and School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK
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253
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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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254
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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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255
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Lu M, Qian Y, Huang L, Xie X, Huang W. Improving the Performance of Microbial Fuel Cells through Anode Manipulation. Chempluschem 2015; 80:1216-1225. [DOI: 10.1002/cplu.201500200] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/13/2015] [Indexed: 12/26/2022]
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256
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Redox Linked Flavin Sites in Extracellular Decaheme Proteins Involved in Microbe-Mineral Electron Transfer. Sci Rep 2015; 5:11677. [PMID: 26126857 PMCID: PMC4486940 DOI: 10.1038/srep11677] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 06/02/2015] [Indexed: 11/29/2022] Open
Abstract
Extracellular microbe-mineral electron transfer is a major driving force for the oxidation of organic carbon in many subsurface environments. Extracellular multi-heme cytochromes of the Shewenella genus play a major role in this process but the mechanism of electron exchange at the interface between cytochrome and acceptor is widely debated. The 1.8 Å x-ray crystal structure of the decaheme MtrC revealed a highly conserved CX8C disulfide that, when substituted for AX8A, severely compromised the ability of S. oneidensis to grow under aerobic conditions. Reductive cleavage of the disulfide in the presence of flavin mononucleotide (FMN) resulted in the reversible formation of a stable flavocytochrome. Similar results were also observed with other decaheme cytochromes, OmcA, MtrF and UndA. The data suggest that these decaheme cytochromes can transition between highly reactive flavocytochromes or less reactive cytochromes, and that this transition is controlled by a redox active disulfide that responds to the presence of oxygen.
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257
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Electrochemical in situ FTIR spectroscopy studies directly extracellular electron transfer of Shewanella oneidensis MR-1. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.04.139] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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258
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Kouzuma A, Kasai T, Hirose A, Watanabe K. Catabolic and regulatory systems in Shewanella oneidensis MR-1 involved in electricity generation in microbial fuel cells. Front Microbiol 2015; 6:609. [PMID: 26136738 PMCID: PMC4468914 DOI: 10.3389/fmicb.2015.00609] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 06/02/2015] [Indexed: 12/12/2022] Open
Abstract
Shewanella oneidensis MR-1 is a facultative anaerobe that respires using a variety of inorganic and organic compounds. MR-1 is also capable of utilizing extracellular solid materials, including anodes in microbial fuel cells (MFCs), as electron acceptors, thereby enabling electricity generation. As MFCs have the potential to generate electricity from biomass waste and wastewater, MR-1 has been extensively studied to identify the molecular systems that are involved in electricity generation in MFCs. These studies have demonstrated the importance of extracellular electron-transfer (EET) pathways that electrically connect the quinone pool in the cytoplasmic membrane to extracellular electron acceptors. Electricity generation is also dependent on intracellular catabolic pathways that oxidize electron donors, such as lactate, and regulatory systems that control the expression of genes encoding the components of catabolic and electron-transfer pathways. In addition, recent findings suggest that cell-surface polymers, e.g., exopolysaccharides, and secreted chemicals, which function as electron shuttles, are also involved in electricity generation. Despite these advances in our knowledge on the EET processes in MR-1, further efforts are necessary to fully understand the underlying intra- and extracellular molecular systems for electricity generation in MFCs. We suggest that investigating how MR-1 coordinates these systems to efficiently transfer electrons to electrodes and conserve electrochemical energy for cell proliferation is important for establishing the biological basis for MFCs.
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Affiliation(s)
- Atsushi Kouzuma
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences , Hachioji, Japan
| | - Takuya Kasai
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences , Hachioji, Japan
| | - Atsumi Hirose
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences , Hachioji, Japan
| | - Kazuya Watanabe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences , Hachioji, Japan
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259
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Kracke F, Vassilev I, Krömer JO. Microbial electron transport and energy conservation - the foundation for optimizing bioelectrochemical systems. Front Microbiol 2015; 6:575. [PMID: 26124754 PMCID: PMC4463002 DOI: 10.3389/fmicb.2015.00575] [Citation(s) in RCA: 307] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 05/25/2015] [Indexed: 12/23/2022] Open
Abstract
Microbial electrochemical techniques describe a variety of emerging technologies that use electrode–bacteria interactions for biotechnology applications including the production of electricity, waste and wastewater treatment, bioremediation and the production of valuable products. Central in each application is the ability of the microbial catalyst to interact with external electron acceptors and/or donors and its metabolic properties that enable the combination of electron transport and carbon metabolism. And here also lies the key challenge. A wide range of microbes has been discovered to be able to exchange electrons with solid surfaces or mediators but only a few have been studied in depth. Especially electron transfer mechanisms from cathodes towards the microbial organism are poorly understood but are essential for many applications such as microbial electrosynthesis. We analyze the different electron transport chains that nature offers for organisms such as metal respiring bacteria and acetogens, but also standard biotechnological organisms currently used in bio-production. Special focus lies on the essential connection of redox and energy metabolism, which is often ignored when studying bioelectrochemical systems. The possibility of extracellular electron exchange at different points in each organism is discussed regarding required redox potentials and effect on cellular redox and energy levels. Key compounds such as electron carriers (e.g., cytochromes, ferredoxin, quinones, flavins) are identified and analyzed regarding their possible role in electrode–microbe interactions. This work summarizes our current knowledge on electron transport processes and uses a theoretical approach to predict the impact of different modes of transfer on the energy metabolism. As such it adds an important piece of fundamental understanding of microbial electron transport possibilities to the research community and will help to optimize and advance bioelectrochemical techniques.
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Affiliation(s)
- Frauke Kracke
- Centre for Microbial Electrochemical Systems, The University of Queensland, Brisbane QLD, Australia ; Advanced Water Management Centre, The University of Queensland, Brisbane QLD, Australia
| | - Igor Vassilev
- Centre for Microbial Electrochemical Systems, The University of Queensland, Brisbane QLD, Australia ; Advanced Water Management Centre, The University of Queensland, Brisbane QLD, Australia
| | - Jens O Krömer
- Centre for Microbial Electrochemical Systems, The University of Queensland, Brisbane QLD, Australia ; Advanced Water Management Centre, The University of Queensland, Brisbane QLD, Australia
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260
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Abstract
Extracellular electron transfer (EET) is a type of microbial respiration that enables electron transfer between microbial cells and extracellular solid materials, including naturally-occurring metal compounds and artificial electrodes. Microorganisms harboring EET abilities have received considerable attention for their various biotechnological applications, in addition to their contribution to global energy and material cycles. In this review, current knowledge on microbial EET and its application to diverse biotechnologies, including the bioremediation of toxic metals, recovery of useful metals, biocorrosion, and microbial electrochemical systems (microbial fuel cells and microbial electrosynthesis), were introduced. Two potential biotechnologies based on microbial EET, namely the electrochemical control of microbial metabolism and electrochemical stimulation of microbial symbiotic reactions (electric syntrophy), were also discussed.
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Affiliation(s)
- Souichiro Kato
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
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261
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Sander M, Hofstetter TB, Gorski CA. Electrochemical analyses of redox-active iron minerals: a review of nonmediated and mediated approaches. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:5862-78. [PMID: 25856208 DOI: 10.1021/acs.est.5b00006] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Redox-active minerals are ubiquitous in the environment and are involved in numerous electron transfer reactions that significantly affect biogeochemical processes and cycles as well as pollutant dynamics. As a consequence, research in different scientific disciplines is devoted to elucidating the redox properties and reactivities of minerals. This review focuses on the characterization of mineral redox properties using electrochemical approaches from an applied (bio)geochemical and environmental analytical chemistry perspective. Establishing redox equilibria between the minerals and working electrodes is a major challenge in electrochemical measurements, which we discuss in an overview of traditional electrochemical techniques. These issues can be overcome with mediated electrochemical analyses in which dissolved redox mediators are used to increase the rate of electron transfer and to facilitate redox equilibration between working electrodes and minerals in both amperometric and potentiometric measurements. Using experimental data on an iron-bearing clay mineral, we illustrate how mediated electrochemical analyses can be employed to derive important thermodynamic and kinetic data on electron transfer to and from structural iron. We summarize anticipated methodological advancements that will further contribute to advance an improved understanding of electron transfer to and from minerals in environmentally relevant redox processes.
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Affiliation(s)
- Michael Sander
- †Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Environmental Chemistry, Swiss Federal Institute of Technology (ETH), Universitätstrasse 16, 8092 Zurich, Switzerland
| | - Thomas B Hofstetter
- ‡Environmental Chemistry, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Ueberlandstrasse 133,8600 Duebendorf, Switzerland
| | - Christopher A Gorski
- §Civil and Environmental Engineering, The Pennsylvania State University, 212 Sackett Building, University Park, Pennsylvania 16802-1408, United States
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262
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Hwang ET, Sheikh K, Orchard KL, Hojo D, Radu V, Lee CY, Ainsworth E, Lockwood C, Gross MA, Adschiri T, Reisner E, Butt JN, Jeuken LJC. A Decaheme Cytochrome as a Molecular Electron Conduit in Dye-Sensitized Photoanodes. ADVANCED FUNCTIONAL MATERIALS 2015; 25:2308-2315. [PMID: 26180522 PMCID: PMC4493899 DOI: 10.1002/adfm.201404541] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 02/05/2015] [Indexed: 06/04/2023]
Abstract
In nature, charge recombination in light-harvesting reaction centers is minimized by efficient charge separation. Here, it is aimed to mimic this by coupling dye-sensitized TiO2 nanocrystals to a decaheme protein, MtrC from Shewanella oneidensis MR-1, where the 10 hemes of MtrC form a ≈7-nm-long molecular wire between the TiO2 and the underlying electrode. The system is assembled by forming a densely packed MtrC film on an ultra-flat gold electrode, followed by the adsorption of approximately 7 nm TiO2 nanocrystals that are modified with a phosphonated bipyridine Ru(II) dye (RuP). The step-by-step construction of the MtrC/TiO2 system is monitored with (photo)electrochemistry, quartz-crystal microbalance with dissipation (QCM-D), and atomic force microscopy (AFM). Photocurrents are dependent on the redox state of the MtrC, confirming that electrons are transferred from the TiO2 nanocrystals to the surface via the MtrC conduit. In other words, in these TiO2/MtrC hybrid photodiodes, MtrC traps the conduction-band electrons from TiO2 before transferring them to the electrode, creating a photobioelectrochemical system in which a redox protein is used to mimic the efficient charge separation found in biological photosystems.
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Affiliation(s)
- Ee Taek Hwang
- School of Biomedical Sciences, University of Leeds Leeds, LS2 9JT, UK E-mail: ; The Astbury Centre for Structural Molecular Biology, University of Leeds Leeds, LS2 9JT, UK
| | - Khizar Sheikh
- School of Biomedical Sciences, University of Leeds Leeds, LS2 9JT, UK E-mail: ; The Astbury Centre for Structural Molecular Biology, University of Leeds Leeds, LS2 9JT, UK
| | - Katherine L Orchard
- Department of Chemistry, University of Cambridge Lensfield Road, Cambridge, CB2 1EW, UK E-mail: ; Advanced Institute for Materials Research, Tohoku University 2-1-1 Katahira Aoba-ku Sendai, Miyagi, 980-8577, Japan E-mail:
| | - Daisuke Hojo
- Advanced Institute for Materials Research, Tohoku University 2-1-1 Katahira Aoba-ku Sendai, Miyagi, 980-8577, Japan E-mail:
| | - Valentin Radu
- School of Biomedical Sciences, University of Leeds Leeds, LS2 9JT, UK E-mail: ; The Astbury Centre for Structural Molecular Biology, University of Leeds Leeds, LS2 9JT, UK
| | - Chong-Yong Lee
- Department of Chemistry, University of Cambridge Lensfield Road, Cambridge, CB2 1EW, UK E-mail:
| | - Emma Ainsworth
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia Norwich Research Park, Norwich, NR4 7TJ, UK E-mail:
| | - Colin Lockwood
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia Norwich Research Park, Norwich, NR4 7TJ, UK E-mail:
| | - Manuela A Gross
- Department of Chemistry, University of Cambridge Lensfield Road, Cambridge, CB2 1EW, UK E-mail:
| | - Tadafumi Adschiri
- Advanced Institute for Materials Research, Tohoku University 2-1-1 Katahira Aoba-ku Sendai, Miyagi, 980-8577, Japan E-mail:
| | - Erwin Reisner
- Department of Chemistry, University of Cambridge Lensfield Road, Cambridge, CB2 1EW, UK E-mail:
| | - Julea N Butt
- Centre for Molecular and Structural Biochemistry, School of Chemistry and School of Biological Sciences, University of East Anglia Norwich Research Park, Norwich, NR4 7TJ, UK E-mail:
| | - Lars J C Jeuken
- School of Biomedical Sciences, University of Leeds Leeds, LS2 9JT, UK E-mail: ; The Astbury Centre for Structural Molecular Biology, University of Leeds Leeds, LS2 9JT, UK
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263
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Migliore A, Nitzan A. Irreversibility in redox molecular conduction: single versus double metal-molecule interfaces. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.01.174] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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264
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Artyushkova K, Cornejo JA, Ista LK, Babanova S, Santoro C, Atanassov P, Schuler AJ. Relationship between surface chemistry, biofilm structure, and electron transfer in Shewanella anodes. Biointerphases 2015; 10:019013. [PMID: 25743616 PMCID: PMC5849046 DOI: 10.1116/1.4913783] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 02/13/2015] [Accepted: 02/18/2015] [Indexed: 11/17/2022] Open
Abstract
A better understanding of how anode surface properties affect growth, development, and activity of electrogenic biofilms has great potential to improve the performance of bioelectrochemical systems such as microbial fuel cells. The aim of this paper was to determine how anodes with specific exposed functional groups (-N(CH3)3 (+), -COOH, -OH, and -CH3), created using ω-substituted alkanethiolates self-assembled monolayers attached to gold, affect the surface properties and functional performance of electrogenic Shewanella oneidensis MR-1 biofilms. A combination of spectroscopic, microscopic, and electrochemical techniques was used to evaluate how electrode surface chemistry influences morphological, chemical, and functional properties of S. oneidensis MR-1 biofilms, in an effort to develop improved electrode materials and structures. Positively charged, highly functionalized, hydrophilic surfaces were beneficial for growth of uniform biofilms with the smallest cluster sizes and intercluster diffusion distances, and yielding the most efficient electron transfer. The authors derived these parameters based on 3D morphological features of biofilms that were directly linked to functional properties of the biofilm during growth and that, during polarization, were directly connected to the efficiency of electron transfer to the anode. Our results indicate that substratum chemistry affects not only primary attachment, but subsequent biofilm development and bacterial physiology.
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Affiliation(s)
- Kateryna Artyushkova
- Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131
| | - Jose A Cornejo
- Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131
| | - Linnea K Ista
- Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131
| | - Sofia Babanova
- Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131
| | - Carlo Santoro
- Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131
| | - Plamen Atanassov
- Department of Chemical and Biological Engineering, Center for Emerging Energy Technology, The University of New Mexico, Albuquerque, New Mexico 87131
| | - Andrew J Schuler
- Department of Civil Engineering, The University of New Mexico, Albuquerque, New Mexico 87131
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265
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Li SL, Nealson KH. Enriching distinctive microbial communities from marine sediments via an electrochemical-sulfide-oxidizing process on carbon electrodes. Front Microbiol 2015; 6:111. [PMID: 25741331 PMCID: PMC4330880 DOI: 10.3389/fmicb.2015.00111] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 01/29/2015] [Indexed: 11/13/2022] Open
Abstract
Sulfide is a common product of marine anaerobic respiration, and a potent reactant biologically and geochemically. Here we demonstrate the impact on microbial communities with the removal of sulfide via electrochemical methods. The use of differential pulse voltammetry revealed that the oxidation of soluble sulfide was seen at +30 mV (vs. SHE) at all pH ranges tested (from pH = 4 to 8), while non-ionized sulfide, which dominated at pH = 4 was poorly oxidized via this process. Two mixed cultures (CAT and LA) were enriched from two different marine sediments (from Catalina Island, CAT; from the Port of Los Angeles, LA) in serum bottles using a seawater medium supplemented with lactate, sulfate, and yeast extract, to obtain abundant biomass. Both CAT and LA cultures were inoculated in electrochemical cells (using yeast-extract-free seawater medium as an electrolyte) equipped with carbon-felt electrodes. In both cases, when potentials of +630 or +130 mV (vs. SHE) were applied, currents were consistently higher at +630 then at +130 mV, indicating more sulfide being oxidized at the higher potential. In addition, higher organic-acid and sulfate conversion rates were found at +630 mV with CAT, while no significant differences were found with LA at different potentials. The results of microbial-community analyses revealed a decrease in diversity for both CAT and LA after electrochemical incubation. In addition, some bacteria (e.g., Clostridium and Arcobacter) not well-known to be capable of extracellular electron transfer, were found to be dominant in the electrochemical cells. Thus, even though the different mixed cultures have different tolerances for sulfide, electrochemical-sulfide removal can lead to major population changes.
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Affiliation(s)
- Shiue-Lin Li
- Department of Earth Science, University of Southern California Los Angeles, CA, USA
| | - Kenneth H Nealson
- Department of Earth Science, University of Southern California Los Angeles, CA, USA
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266
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Tikhonova TV, Popov VO. Structural and functional studies of multiheme cytochromes c involved in extracellular electron transport in bacterial dissimilatory metal reduction. BIOCHEMISTRY (MOSCOW) 2015; 79:1584-601. [DOI: 10.1134/s0006297914130094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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267
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Yang Y, Xiang Y, Sun G, Wu WM, Xu M. Electron acceptor-dependent respiratory and physiological stratifications in biofilms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:196-202. [PMID: 25495895 DOI: 10.1021/es504546g] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Bacterial respiration is an essential driving force in biogeochemical cycling and bioremediation processes. Electron acceptors respired by bacteria often have solid and soluble forms that typically coexist in the environment. It is important to understand how sessile bacteria attached to solid electron acceptors respond to ambient soluble alternative electron acceptors. Microbial fuel cells (MFCs) provide a useful tool to investigate this interaction. In MFCs with Shewanella decolorationis, azo dye was used as an alternative electron acceptor in the anode chamber. Different respiration patterns were observed for biofilm and planktonic cells, with planktonic cells preferred to respire with azo dye while biofilm cells respired with both the anode and azo dye. The additional azo respiration dissipated the proton accumulation within the anode biofilm. There was a large redox potential gap between the biofilms and anode surface. Changing cathodic conditions caused immediate effects on the anode potential but not on the biofilm potential. Biofilm viability showed an inverse and respiration-dependent profile when respiring with only the anode or azo dye and was enhanced when respiring with both simultaneously. These results provide new insights into the bacterial respiration strategies in environments containing multiple electron acceptors and support an electron-hopping mechanism within Shewanella electrode-respiring biofilms.
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Affiliation(s)
- Yonggang Yang
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology , Guangzhou, China 510070
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268
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DENG X, NAKAMURA R, HASHIMOTO K, OKAMOTO A. Electron Extraction from an Extracellular Electrode by Desulfovibrio ferrophilus Strain IS5 Without Using Hydrogen as an Electron Carrier. ELECTROCHEMISTRY 2015. [DOI: 10.5796/electrochemistry.83.529] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Xiao DENG
- Department of Applied Chemistry, University of Tokyo
| | - Ryuhei NAKAMURA
- Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science
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269
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Ding CM, Lv ML, Zhu Y, Jiang L, Liu H. Wettability-Regulated Extracellular Electron Transfer from the Living Organism ofShewanella loihicaPV-4. Angew Chem Int Ed Engl 2014; 54:1446-51. [DOI: 10.1002/anie.201409163] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 10/27/2014] [Indexed: 12/11/2022]
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270
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Ding CM, Lv ML, Zhu Y, Jiang L, Liu H. Wettability-Regulated Extracellular Electron Transfer from the Living Organism ofShewanella loihicaPV-4. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201409163] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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271
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Liu Y, Wang Z, Liu J, Levar C, Edwards MJ, Babauta JT, Kennedy DW, Shi Z, Beyenal H, Bond DR, Clarke TA, Butt JN, Richardson DJ, Rosso KM, Zachara JM, Fredrickson JK, Shi L. A trans-outer membrane porin-cytochrome protein complex for extracellular electron transfer by Geobacter sulfurreducens PCA. ENVIRONMENTAL MICROBIOLOGY REPORTS 2014; 6:776-85. [PMID: 25139405 PMCID: PMC4282303 DOI: 10.1111/1758-2229.12204] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 08/14/2014] [Indexed: 05/19/2023]
Abstract
The multi-heme, outer membrane c-type cytochrome (c-Cyt) OmcB of Geobacter sulfurreducens was previously proposed to mediate electron transfer across the outer membrane. However, the underlying mechanism has remained uncharacterized. In G. sulfurreducens, the omcB gene is part of two tandem four-gene clusters, each is predicted to encode a transcriptional factor (OrfR/OrfS), a porin-like outer membrane protein (OmbB/OmbC), a periplasmic c-type cytochrome (OmaB/OmaC) and an outer membrane c-Cyt (OmcB/OmcC) respectively. Here, we showed that OmbB/OmbC, OmaB/OmaC and OmcB/OmcC of G. sulfurreducens PCA formed the porin-cytochrome (Pcc) protein complexes, which were involved in transferring electrons across the outer membrane. The isolated Pcc protein complexes reconstituted in proteoliposomes transferred electrons from reduced methyl viologen across the lipid bilayer of liposomes to Fe(III)-citrate and ferrihydrite. The pcc clusters were found in all eight sequenced Geobacter and 11 other bacterial genomes from six different phyla, demonstrating a widespread distribution of Pcc protein complexes in phylogenetically diverse bacteria. Deletion of ombB-omaB-omcB-orfS-ombC-omaC-omcC gene clusters had no impact on the growth of G. sulfurreducens PCA with fumarate but diminished the ability of G. sulfurreducens PCA to reduce Fe(III)-citrate and ferrihydrite. Complementation with the ombB-omaB-omcB gene cluster restored the ability of G. sulfurreducens PCA to reduce Fe(III)-citrate and ferrihydrite.
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Affiliation(s)
- Yimo Liu
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
| | - Zheming Wang
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
| | - Juan Liu
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
- † College of Environmental Sciences and Engineering, Peking University, China
| | - Caleb Levar
- Department of Microbiology, University of MinnesotaSt. Paul, MN, 55108, USA
| | - Marcus J Edwards
- Center for Molecular and Structural Biochemistry, School of Biological Sciences and School of Chemistry, University of East AngliaNorwich, NR4 7TJ, UK
| | - Jerome T Babauta
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State UniversityPullman, WA, 99164, USA
| | - David W Kennedy
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
| | - Zhi Shi
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
- ‡ Analytical Technology Center, The Dow Chemical Company, Freeport, TX, 77541, USA
| | - Haluk Beyenal
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State UniversityPullman, WA, 99164, USA
| | - Daniel R Bond
- Department of Microbiology, University of MinnesotaSt. Paul, MN, 55108, USA
| | - Thomas A Clarke
- Center for Molecular and Structural Biochemistry, School of Biological Sciences and School of Chemistry, University of East AngliaNorwich, NR4 7TJ, UK
| | - Julea N Butt
- Center for Molecular and Structural Biochemistry, School of Biological Sciences and School of Chemistry, University of East AngliaNorwich, NR4 7TJ, UK
| | - David J Richardson
- Center for Molecular and Structural Biochemistry, School of Biological Sciences and School of Chemistry, University of East AngliaNorwich, NR4 7TJ, UK
| | - Kevin M Rosso
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
| | - John M Zachara
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
| | - James K Fredrickson
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
| | - Liang Shi
- Fundamental & Computational Sciences Directorate, Pacific Northwest National LaboratoryRichland, WA, 99352, USA
- * For correspondence. E-mail ; Tel. 509 371 6967; Fax 509 376 1632
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272
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Extracellular Electron Transfer Mediated by Flavins in Gram-positive Bacillus sp. WS-XY1 and Yeast Pichia stipitis. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.09.096] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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273
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Engineering microbial electrocatalysis for chemical and fuel production. Curr Opin Biotechnol 2014; 29:93-8. [DOI: 10.1016/j.copbio.2014.03.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 03/07/2014] [Accepted: 03/11/2014] [Indexed: 11/19/2022]
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274
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Kinetic Monte Carlo Simulations and Molecular Conductance Measurements of the Bacterial Decaheme Cytochrome MtrF. ChemElectroChem 2014. [DOI: 10.1002/celc.201402211] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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275
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Kalathil S, Hashimoto K, Okamoto A. Effect of Ionic Strength on the Rate of Extracellular Electron Transport inShewanella oneidensisMR-1 through Bound-Flavin Semiquinones. ChemElectroChem 2014. [DOI: 10.1002/celc.201402195] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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276
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Flavin Redox Bifurcation as a Mechanism for Controlling the Direction of Electron Flow during Extracellular Electron Transfer. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201407004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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277
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Okamoto A, Hashimoto K, Nealson KH. Flavin Redox Bifurcation as a Mechanism for Controlling the Direction of Electron Flow during Extracellular Electron Transfer. Angew Chem Int Ed Engl 2014; 53:10988-91. [DOI: 10.1002/anie.201407004] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Indexed: 11/12/2022]
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278
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Electroactive bacteria—molecular mechanisms and genetic tools. Appl Microbiol Biotechnol 2014; 98:8481-95. [DOI: 10.1007/s00253-014-6005-z] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/28/2014] [Accepted: 07/30/2014] [Indexed: 12/15/2022]
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279
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Wu Y, Liu T, Li X, Li F. Exogenous electron shuttle-mediated extracellular electron transfer of Shewanella putrefaciens 200: electrochemical parameters and thermodynamics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:9306-9314. [PMID: 25058026 DOI: 10.1021/es5017312] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Despite the importance of exogenous electron shuttles (ESs) in extracellular electron transfer (EET), a lack of understanding of the key properties of ESs is a concern given their different influences on EET processes. Here, the ES-mediated EET capacity of Shewanella putrefaciens 200 (SP200) was evaluated by examining the electricity generated in a microbial fuel cell. The results indicated that all the ESs substantially accelerated the current generation compared to only SP200. The current and polarization parameters were linearly correlated with both the standard redox potential (E(ES)(0)) and the electron accepting capacity (EAC) of the ESs. A thermodynamic analysis of the electron transfer from the electron donor to the electrode suggested that the EET from c-type cytochromes (c-Cyts) to ESs is a crucial step causing the differences in EET capacities among various ESs. Based on the derived equations, both E(ES)(0) and EAC can quantitatively determine potential losses (ΔE) that reflect the potential loss of the ES-mediated EET. In situ spectral kinetic analysis of ES reduction by c-Cyts in a living SP200 suspension was first investigated with the E(ES), E(c-Cyt), and ΔE values being calculated. This study can provide a comprehensive understanding of the role of ESs in EET.
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Affiliation(s)
- Yundang Wu
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences , Guangzhou, P. R. China
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280
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Okamoto A, Nakamura R, Nealson KH, Hashimoto K. Bound Flavin Model Suggests Similar Electron-Transfer Mechanisms inShewanellaandGeobacter. ChemElectroChem 2014. [DOI: 10.1002/celc.201402151] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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281
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Kouzuma A, Oba H, Tajima N, Hashimoto K, Watanabe K. Electrochemical selection and characterization of a high current-generating Shewanella oneidensis mutant with altered cell-surface morphology and biofilm-related gene expression. BMC Microbiol 2014; 14:190. [PMID: 25028134 PMCID: PMC4112983 DOI: 10.1186/1471-2180-14-190] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 07/10/2014] [Indexed: 01/06/2023] Open
Abstract
Background Shewanella oneidensis MR-1 exhibits extracellular electron transfer (EET) activity that is influenced by various cellular components, including outer-membrane cytochromes, cell-surface polysaccharides (CPS), and regulatory proteins. Here, a random transposon-insertion mutant library of S. oneidensis MR-1 was screened after extended cultivation in electrochemical cells (ECs) with a working electrode poised at +0.2 V (vs. Ag/AgCl) to isolate mutants that adapted to electrode-respiring conditions and identify as-yet-unknown EET-related factors. Results Several mutants isolated from the enrichment culture exhibited rough morphology and extraordinarily large colonies on agar plates compared to wild-type MR-1. One of the isolated mutants, designated strain EC-2, produced 90% higher electric current than wild-type MR-1 in ECs and was found to have a transposon inserted in the SO_1860 (uvrY) gene, which encodes a DNA-binding response regulator of the BarA/UvrY two-component regulatory system. However, an in-frame deletion mutant of SO_1860 (∆SO_1860) did not exhibit a similar level of current generation as that of EC-2, suggesting that the enhanced current-generating capability of EC-2 was not simply due to the disruption of SO_1860. In both EC-2 and ∆SO_1860, the transcription of genes related to CPS synthesis was decreased compared to wild-type MR-1, suggesting that CPS negatively affects current generation. In addition, transcriptome analyses revealed that a number of genes, including those involved in biofilm formation, were differentially expressed in EC-2 compared to those in ∆SO_1860. Conclusions The present results indicate that the altered expression of the genes related to CPS biosynthesis and biofilm formation is associated with the distinct morphotype and high current-generating capability of strain EC-2, suggesting an important role of these genes in determining the EET activity of S. oneidensis.
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Affiliation(s)
- Atsushi Kouzuma
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji 192-0392, Tokyo, Japan.
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282
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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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283
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Yang Y, Xiang Y, Xia C, Wu WM, Sun G, Xu M. Physiological and electrochemical effects of different electron acceptors on bacterial anode respiration in bioelectrochemical systems. BIORESOURCE TECHNOLOGY 2014; 164:270-275. [PMID: 24862003 DOI: 10.1016/j.biortech.2014.04.098] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/23/2014] [Accepted: 04/25/2014] [Indexed: 06/03/2023]
Abstract
To understand the interactions between bacterial electrode respiration and the other ambient bacterial electron acceptor reductions, alternative electron acceptors (nitrate, Fe2O3, fumarate, azo dye MB17) were added singly or multiply into Shewanella decolorationis microbial fuel cells (MFCs). All the added electron acceptors were reduced simultaneously with current generation. Adding nitrate or MB17 resulted in more rapid cell growth, higher flavin concentration and higher biofilm metabolic viability, but lower columbic efficiency (CE) and normalized energy recovery (NER) while the CE and NER were enhanced by Fe2O3 or fumarate. The added electron acceptors also significantly influenced the cyclic voltammetry profile of anode biofilm probably via altering the cytochrome c expression. The highest power density was observed in MFCs added with MB17 due to the electron shuttle role of the naphthols from MB17 reduction. The results provided important information for MFCs applied in practical environments where contains various electron acceptors.
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Affiliation(s)
- Yonggang Yang
- State Key Laboratory of Applied Microbiology Southern China, Guangzhou, China; Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou, China
| | - Yinbo Xiang
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou, China
| | - Chunyu Xia
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou, China
| | - Wei-Min Wu
- Department of Civil & Environmental Engineering, Center for Sustainable Development & Global Competitiveness, Stanford University, Stanford 94305-4020, USA
| | - Guoping Sun
- State Key Laboratory of Applied Microbiology Southern China, Guangzhou, China; Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou, China
| | - Meiying Xu
- State Key Laboratory of Applied Microbiology Southern China, Guangzhou, China; Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou, China.
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284
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Paquete CM, Fonseca BM, Cruz DR, Pereira TM, Pacheco I, Soares CM, Louro RO. Exploring the molecular mechanisms of electron shuttling across the microbe/metal space. Front Microbiol 2014; 5:318. [PMID: 25018753 PMCID: PMC4073285 DOI: 10.3389/fmicb.2014.00318] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 06/10/2014] [Indexed: 11/27/2022] Open
Abstract
Dissimilatory metal reducing organisms play key roles in the biogeochemical cycle of metals as well as in the durability of submerged and buried metallic structures. The molecular mechanisms that support electron transfer across the microbe-metal interface in these organisms remain poorly explored. It is known that outer membrane proteins, in particular multiheme cytochromes, are essential for this type of metabolism, being responsible for direct and indirect, via electron shuttles, interaction with the insoluble electron acceptors. Soluble electron shuttles such as flavins, phenazines, and humic acids are known to enhance extracellular electron transfer. In this work, this phenomenon was explored. All known outer membrane decaheme cytochromes from Shewanella oneidensis MR-1 with known metal terminal reductase activity and a undecaheme cytochrome from Shewanella sp. HRCR-6 were expressed and purified. Their interactions with soluble electron shuttles were studied using stopped-flow kinetics, NMR spectroscopy, and molecular simulations. The results show that despite the structural similarities, expected from the available structural data and sequence homology, the detailed characteristics of their interactions with soluble electron shuttles are different. MtrC and OmcA appear to interact with a variety of different electron shuttles in the close vicinity of some of their hemes, and with affinities that are biologically relevant for the concentrations typical found in the medium for this type of compounds. All data support a view of a distant interaction between the hemes of MtrF and the electron shuttles. For UndA a clear structural characterization was achieved for the interaction with AQDS a humic acid analog. These results provide guidance for future work of the manipulation of these proteins toward modulation of their role in metal attachment and reduction.
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Affiliation(s)
- Catarina M Paquete
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Bruno M Fonseca
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Davide R Cruz
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Tiago M Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Isabel Pacheco
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Cláudio M Soares
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Ricardo O Louro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
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285
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Dolch K, Danzer J, Kabbeck T, Bierer B, Erben J, Förster AH, Maisch J, Nick P, Kerzenmacher S, Gescher J. Characterization of microbial current production as a function of microbe-electrode-interaction. BIORESOURCE TECHNOLOGY 2014; 157:284-92. [PMID: 24566287 DOI: 10.1016/j.biortech.2014.01.112] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/24/2014] [Accepted: 01/27/2014] [Indexed: 05/15/2023]
Abstract
Microbe-electrode-interactions are keys for microbial fuel cell technology. Nevertheless, standard measurement routines to analyze the interplay of microbial physiology and material characteristics have not been introduced yet. In this study, graphite anodes with varying surface properties were evaluated using pure cultures of Shewanella oneidensis and Geobacter sulfurreducens, as well as defined and undefined mixed cultures. The evaluation routine consisted of a galvanostatic period, a current sweep and an evaluation of population density. The results show that surface area correlates only to a certain extent with population density and anode performance. Furthermore, the study highlights a strain-specific microbe-electrode-interaction, which is affected by the introduction of another microorganism. Moreover, evidence is provided for the possibility of translating results from pure culture to undefined mixed species experiments. This is the first study on microbe-electrode-interaction that systematically integrates and compares electrochemical and biological data.
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Affiliation(s)
- Kerstin Dolch
- Institute for Applied Biosciences, Department of Applied Biology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
| | - Joana Danzer
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - Tobias Kabbeck
- Institute for Applied Biosciences, Department of Applied Biology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
| | - Benedikt Bierer
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - Johannes Erben
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - Andreas H Förster
- Institute for Applied Biosciences, Department of Applied Biology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
| | - Jan Maisch
- Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Kaiserstrasse 2, 76131 Karlsruhe, Germany.
| | - Peter Nick
- Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology, Kaiserstrasse 2, 76131 Karlsruhe, Germany.
| | - Sven Kerzenmacher
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - Johannes Gescher
- Institute for Applied Biosciences, Department of Applied Biology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
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286
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Cao H, Qiao Y, Meng F, Liu X. Spacing-Dependent Antimicrobial Efficacy of Immobilized Silver Nanoparticles. J Phys Chem Lett 2014; 5:743-748. [PMID: 26270846 DOI: 10.1021/jz5000269] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Silver nanoparticles (Ag NPs) with a similar mean particle diameter (∼5.0 nm) but distinguished dispersion densities were in situ fabricated and immobilized on plasma-sprayed titanium oxide coatings by a silver plasma immersion ion implantation process (Ag PIII). Experiments and theoretical predictions demonstrated that the efficacy of these Ag NPs against bacteria relies on their electron storage capability, which is the interparticle distance associated in the dark, and it is inversely dose-dependent. A particle population with a relatively large spacing distance is superior in concentrating the electrons extruded by bacterial cells, activating oxidative reactions, and disrupting the bacterial cells. The finding opens up a new window leading to active design and control of the interactions between materials and biological systems.
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Affiliation(s)
- Huiliang Cao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Yuqin Qiao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Fanhao Meng
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Xuanyong Liu
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
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287
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Lu Y, Nishio K, Matsuda S, Toshima Y, Ito H, Konno T, Ishihara K, Kato S, Hashimoto K, Nakanishi S. Regulation of the cyanobacterial circadian clock by electrochemically controlled extracellular electron transfer. Angew Chem Int Ed Engl 2014; 53:2208-11. [PMID: 24573996 DOI: 10.1002/anie.201309560] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Indexed: 12/20/2022]
Abstract
There is growing awareness that circadian clocks are closely related to the intracellular redox state across a range of species. As the redox state is determined by the exchange of the redox species, electrochemically controlled extracellular electron transfer (EC-EET), a process in which intracellular electrons are exchanged with extracellular electrodes, is a promising approach for the external regulation of circadian clocks. Herein, we discuss whether the circadian clock can be regulated by EC-EET using the cyanobacterium Synechococcus elongatus PCC7942 as a model system. In vivo monitoring of chlorophyll fluorescence revealed that the redox state of the plastoquionone pool could be controlled with EC-EET by simply changing the electrode potential. As a result, the endogenous circadian clock of S. elongatus cells was successfully entrained through periodically modulated EC-EET by emulating the natural light/dark cycle, even under constant illumination conditions. This is the first example of regulating the biological clock by electrochemistry.
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Affiliation(s)
- Yue Lu
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)
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288
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Lu Y, Nishio K, Matsuda S, Toshima Y, Ito H, Konno T, Ishihara K, Kato S, Hashimoto K, Nakanishi S. Regulation of the Cyanobacterial Circadian Clock by Electrochemically Controlled Extracellular Electron Transfer. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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289
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Kaneshiro H, Takano K, Takada Y, Wakisaka T, Tachibana T, Azuma M. A milliliter-scale yeast-based fuel cell with high performance. Biochem Eng J 2014. [DOI: 10.1016/j.bej.2013.12.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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290
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Breuer M, Rosso KM, Blumberger J. Electron flow in multiheme bacterial cytochromes is a balancing act between heme electronic interaction and redox potentials. Proc Natl Acad Sci U S A 2014; 111:611-6. [PMID: 24385579 PMCID: PMC3896160 DOI: 10.1073/pnas.1316156111] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The naturally widespread process of electron transfer from metal reducing bacteria to extracellular solid metal oxides entails unique biomolecular machinery optimized for long-range electron transport. To perform this function efficiently, microorganisms have adapted multiheme c-type cytochromes to arrange heme cofactors into wires that cooperatively span the cellular envelope, transmitting electrons along distances greater than 100 Å. Implications and opportunities for bionanotechnological device design are self-evident. However, at the molecular level, how these proteins shuttle electrons along their heme wires, navigating intraprotein intersections and interprotein interfaces efficiently, remains a mystery thus far inaccessible to experiment. To shed light on this critical topic, we carried out extensive quantum mechanics/molecular mechanics simulations to calculate stepwise heme-to-heme electron transfer rates in the recently crystallized outer membrane deca-heme cytochrome MtrF. By solving a master equation for electron hopping, we estimate an intrinsic, maximum possible electron flux through solvated MtrF of 10(4)-10(5) s(-1), consistent with recently measured rates for the related multiheme protein complex MtrCAB. Intriguingly, our calculations show that the rapid electron transport through MtrF is the result of a clear correlation between heme redox potential and the strength of electronic coupling along the wire: thermodynamically uphill steps occur only between electronically well-connected stacked heme pairs. This observation suggests that the protein evolved to harbor low-potential hemes without slowing down electron flow. These findings are particularly profound in light of the apparently well-conserved staggered cross-heme wire structural motif in functionally related outer membrane proteins.
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Affiliation(s)
- Marian Breuer
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom; and
| | - Kevin M. Rosso
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352
| | - Jochen Blumberger
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom; and
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291
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Tan SLJ, Kan JM, Webster RD. Differences in proton-coupled electron-transfer reactions of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) between buffered and unbuffered aqueous solutions. J Phys Chem B 2013; 117:13755-66. [PMID: 24079606 DOI: 10.1021/jp4069619] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electrochemical reduction mechanisms of flavin mononucleotide (FMN) in buffered aqueous solutions at pH 3-11 and unbuffered aqueous solutions at pH 2-11 were examined in detail using variable-scan-rate cyclic voltammetry (ν = 0.1-20 V s(-1)), controlled-potential bulk electrolysis, UV-vis spectroscopy, and rotating-disk-electrode voltammetry. In buffered solutions at pH 3-5, FMN undergoes a two-electron/two-proton (2e(-)/2H(+)) reduction to form FMNH2 at all scan rates. When the buffered pH is increased to 7-9, FMN undergoes a 2e(-) reduction to form FMN(2-), which initially undergoes hydrogen bonding with water molecules, followed by protonation to form FMNH(-). At a low voltammetric scan rate of 0.1 V s(-1), the protonation reaction has sufficient time to take place. However, at a higher scan rate of 20 V s(-1), the proton-transfer reaction is outrun, and upon reversal of the scan direction, less of the FMNH(-) is available for oxidation, causing its oxidation peak to decrease in magnitude. In unbuffered aqueous solutions, three major voltammetric waves were observed in different pH ranges. At low pH in unbuffered solutions, where [H(+)] ≥ [FMN], (FMN)H(-) undergoes a 2e(-)/2H(+) reduction to form (FMNH2)H(-) (wave 1), similar to the mechanism in buffered aqueous solutions at low pH. At midrange pH values (unbuffered), where pH ≤ pKa of the phosphate group and [FMN] ≥ [H(+)], (FMN)H(-) undergoes a 2e(-) reduction to form (FMN(2-))H(-) (wave 2), similar to the mechanism in buffered aqueous solutions at high pH. At high pH (unbuffered), where pH ≥ pKa = 6.2 of the phosphate group, the phosphate group loses its second proton to be fully deprotonated, forming (FMN)(2-), and this species undergoes a 2e(-) reduction to form (FMN(2-))(2-) (wave 3).
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Affiliation(s)
- Serena L J Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371
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292
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Kipf E, Koch J, Geiger B, Erben J, Richter K, Gescher J, Zengerle R, Kerzenmacher S. Systematic screening of carbon-based anode materials for microbial fuel cells with Shewanella oneidensis MR-1. BIORESOURCE TECHNOLOGY 2013; 146:386-392. [PMID: 23954244 DOI: 10.1016/j.biortech.2013.07.076] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/10/2013] [Accepted: 07/12/2013] [Indexed: 06/02/2023]
Abstract
We present a systematic screening of carbon-based anode materials for microbial fuel cells with Shewanella oneidensis MR-1. Under anoxic conditions nanoporous activated carbon cloth is a superior anode material in terms of current density normalized to the projected anode area and anode volume (24.0±0.3 μA cm(-2) and 482±7 μA cm(-3) at -0.2 vs. SCE, respectively). The good performance can be attributed to the high specific surface area of the material, which is available for mediated electron transfer through self-secreted flavins. Under aerated conditions no influence of the specific surface area is observed, which we attribute to a shift from primary indirect electron transfer by mediators to direct electron transfer via adherent cells. Furthermore, we show that an aerated initial growth phase enhances the current density under subsequent anoxic conditions fivefold when compared to a similar experiment that was conducted under permanently anoxic conditions.
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Affiliation(s)
- Elena Kipf
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - Julia Koch
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Bettina Geiger
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Johannes Erben
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
| | - Katrin Richter
- Institute for Applied Biosciences, Department of Applied Biology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
| | - Johannes Gescher
- Institute for Applied Biosciences, Department of Applied Biology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
| | - Roland Zengerle
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany; BIOSS - Centre for Biological Signalling Studies, University of Freiburg, 79110 Freiburg, Germany.
| | - Sven Kerzenmacher
- Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany.
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293
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Matsuda S, Liu H, Kouzuma A, Watanabe K, Hashimoto K, Nakanishi S. Electrochemical gating of tricarboxylic acid cycle in electricity-producing bacterial cells of Shewanella. PLoS One 2013; 8:e72901. [PMID: 23977370 PMCID: PMC3748093 DOI: 10.1371/journal.pone.0072901] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/16/2013] [Indexed: 01/15/2023] Open
Abstract
Energy-conversion systems mediated by bacterial metabolism have recently attracted much attention, and therefore, demands for tuning of bacterial metabolism are increasing. It is widely recognized that intracellular redox atmosphere which is generally tuned by dissolved oxygen concentration or by appropriate selection of an electron acceptor for respiration is one of the important factors determining the bacterial metabolism. In general, electrochemical approaches are valuable for regulation of redox-active objects. However, the intracellular redox conditions are extremely difficult to control electrochemically because of the presence of insulative phospholipid bilayer membranes. In the present work, the limitation can be overcome by use of the bacterial genus Shewanella, which consists of species that are able to respire via cytochromes abundantly expressed in their outer-membrane with solid-state electron acceptors, including anodes. The electrochemical characterization and the gene expression analysis revealed that the activity of tricarboxylic acid (TCA) cycle in Shewanella cells can be reversibly gated simply by changing the anode potential. Importantly, our present results for Shewanella cells cultured in an electrochemical system under poised potential conditions showed the opposite relationship between the current and electron acceptor energy level, and indicate that this unique behavior originates from deactivation of the TCA cycle in the (over-)oxidative region. Our result obtained in this study is the first demonstration of the electrochemical gating of TCA cycle of living cells. And we believe that our findings will contribute to a deeper understanding of redox-dependent regulation systems in living cells, in which the intracellular redox atmosphere is a critical factor determining the regulation of various metabolic and genetic processes.
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Affiliation(s)
- Shoichi Matsuda
- Department of Applied Chemistry, the University of Tokyo, Tokyo, Japan
| | - Huan Liu
- Exploratory Research for Advanced Technology/Japan Science and Technology Agency, HASHIMOTO Light Energy Conversion Project, Tokyo, Japan
| | - Atsushi Kouzuma
- Exploratory Research for Advanced Technology/Japan Science and Technology Agency, HASHIMOTO Light Energy Conversion Project, Tokyo, Japan
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Kazuya Watanabe
- Research Center for Advanced Science and Technology, the University of Tokyo, Tokyo, Japan
- Exploratory Research for Advanced Technology/Japan Science and Technology Agency, HASHIMOTO Light Energy Conversion Project, Tokyo, Japan
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Kazuhito Hashimoto
- Department of Applied Chemistry, the University of Tokyo, Tokyo, Japan
- Research Center for Advanced Science and Technology, the University of Tokyo, Tokyo, Japan
- Exploratory Research for Advanced Technology/Japan Science and Technology Agency, HASHIMOTO Light Energy Conversion Project, Tokyo, Japan
- * E-mail: ; (KH)
| | - Shuji Nakanishi
- Research Center for Advanced Science and Technology, the University of Tokyo, Tokyo, Japan
- Exploratory Research for Advanced Technology/Japan Science and Technology Agency, HASHIMOTO Light Energy Conversion Project, Tokyo, Japan
- * E-mail: ; (KH)
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294
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Controlling electron transfer at the microbe-mineral interface. Proc Natl Acad Sci U S A 2013; 110:7537-8. [PMID: 23630260 DOI: 10.1073/pnas.1305244110] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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