Disparity of Cytochrome Utilization in Anodic and Cathodic Extracellular Electron Transfer Pathways of <i>Geobacter sulfurreducens</i> Biofilms.
Ly, Khoa H
Greer, Heather F
Journal of the American Chemical Society
American Chemical Society (ACS)
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Heidary, N., Kornienko, N., Kalathil, S., Fang, X., Ly, K. H., Greer, H. F., & Reisner, E. (2020). Disparity of Cytochrome Utilization in Anodic and Cathodic Extracellular Electron Transfer Pathways of <i>Geobacter sulfurreducens</i> Biofilms.. Journal of the American Chemical Society, 142 (11), 5194-5203. https://doi.org/10.1021/jacs.9b13077
Extracellular electron transfer (EET) in microorganisms is prevalent in nature and has been utilized in functional bioelectrochemical systems. EET of Geobacter sulfurreducens has been extensively studied and has been revealed to be facilitated through c-type cytochromes, which mediate charge between the electrode and G. sulfurreducens in anodic mode. However, the EET pathway of cathodic conversion of fumarate to succinate is still under debate. Here, we apply a variety of analytical methods, including electrochemistry, UV-Vis absorption and resonance Raman spectroscopy, quartz crystal microbalance with dissipation, and electron microscopy, to understand the involvement of cytochromes and other possible electron mediating species in the switching between anodic and cathodic reaction modes. Switching the applied bias for a G. sulfurreducens biofilm coupled to investigating the quantity and function of cytochromes, as well as the emergence of Fe-containing particles on the cell membrane, we provide evidence of a diminished role of cytochromes in cathodic EET. The work sheds light on the mechanisms of G. sulfurreducens biofilm growth and suggests the possible existence of a nonheme, iron-involving EET process in cathodic mode.
Biofilms, Geobacter, Iron, Acetates, Succinic Acid, Cytochrome c Group, Bacterial Proteins, Electrodes, Oxidation-Reduction, Electrons, Electrochemical Techniques
N.K. was supported by a Royal Society Newton International Fellowship, NF160054. E.R., X.F. and N.H. acknowledge the European Research Council (ERC) Consolidator Grant “MatEnSAP” (682833). S. K. was supported by a Marie Skłodowska-Curie Fellowship (EMES, 744317). K. H. Ly acknowledges the Open Topic Postdoc Programme of the Technische Universität Dresden and the Marie Sklodowska Curie IF, GAN 701192. The TEM was funded through the EPSRC underpinning multi-user equipment call (EP/P030467/1)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (701192)
ECH2020 EUROPEAN RESEARCH COUNCIL (ERC) (682833)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (744317)
External DOI: https://doi.org/10.1021/jacs.9b13077
This record's URL: https://www.repository.cam.ac.uk/handle/1810/302457
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