TY - JOUR
T1 - Electron transfer mechanism in Shewanella loihica PV-4 biofilms formed at graphite electrode
AU - Jain, Anand
AU - Zhang, Xiaoming
AU - Pastorella, Gabriele
AU - Connolly, Jack O.
AU - Barry, Niamh
AU - Woolley, Robert
AU - Krishnamurthy, Satheesh
AU - Marsili, Enrico
N1 - Funding Information:
Anand Jain and Xiaoming Zhang are supported by the Irish Research Council for Science, Engineering and Technology (IRCSET)—EMPOWER post-doctoral fellowship. Gabriele Pastorella is supported by the Environmental Protection Agency (Ireland)—PhD fellowship. Enrico Marsili is supported by the EU-FP7 Marie Curie International Reintegration Grant.
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2012/10
Y1 - 2012/10
N2 - Electron transfer mechanisms in Shewanella loihica PV-4 viable biofilms formed at graphite electrodes were investigated in potentiostat-controlled electrochemical cells poised at oxidative potentials (0.2V vs. Ag/AgCl). Chronoamperometry (CA) showed a repeatable biofilm growth of S. loihica PV-4 on graphite electrode. CA, cyclic voltammetry (CV) and its first derivative shows that both direct electron transfer (DET) mediated electron transfer (MET) mechanism contributes to the overall anodic (oxidation) current. The maximum anodic current density recorded on graphite was 90μAcm-2. Fluorescence emission spectra shows increased concentration of quinone derivatives and riboflavin in the cell-free supernatant as the biofilm grows. Differential pulse voltammetry (DPV) show accumulation of riboflavin at the graphite interface, with the increase in incubation period. This is the first study to observe a gradual shift from DET to MET mechanism in viable S. loihica PV-4 biofilms.
AB - Electron transfer mechanisms in Shewanella loihica PV-4 viable biofilms formed at graphite electrodes were investigated in potentiostat-controlled electrochemical cells poised at oxidative potentials (0.2V vs. Ag/AgCl). Chronoamperometry (CA) showed a repeatable biofilm growth of S. loihica PV-4 on graphite electrode. CA, cyclic voltammetry (CV) and its first derivative shows that both direct electron transfer (DET) mediated electron transfer (MET) mechanism contributes to the overall anodic (oxidation) current. The maximum anodic current density recorded on graphite was 90μAcm-2. Fluorescence emission spectra shows increased concentration of quinone derivatives and riboflavin in the cell-free supernatant as the biofilm grows. Differential pulse voltammetry (DPV) show accumulation of riboflavin at the graphite interface, with the increase in incubation period. This is the first study to observe a gradual shift from DET to MET mechanism in viable S. loihica PV-4 biofilms.
KW - Electroactive biofilms
KW - Extracellular electron transfer
KW - Graphite electrode
KW - Mediated electron transfer
KW - Shewanella loihica PV-4
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U2 - 10.1016/j.bioelechem.2011.12.012
DO - 10.1016/j.bioelechem.2011.12.012
M3 - Article
C2 - 22281091
AN - SCOPUS:84865183811
VL - 87
SP - 28
EP - 32
JO - Bioelectrochemistry and Bioenergetics
JF - Bioelectrochemistry and Bioenergetics
SN - 1567-5394
ER -