The Open UniversitySkip to content

Electron transfer mechanism in Shewanella loihica PV-4 biofilms formed at graphite electrode

Jain, A.; Zhang, X.; Pastorella, G.; Connolly, J.O.; Barry, N.; Woolley, R.; Krishnamurthy, S. and Marsili, E. (2012). Electron transfer mechanism in Shewanella loihica PV-4 biofilms formed at graphite electrode. Bioelectrochemistry, 87 pp. 28–32.

DOI (Digital Object Identifier) Link:
Google Scholar: Look up in Google Scholar


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.

Item Type: Journal Article
Copyright Holders: 2012 Elsevier B.V.
ISSN: 1567-5394
Keywords: Ag/AgCl; anodic current density; biofilm growth; cell-free; differential pulse voltammetry; direct electron transfer; electroactive; electron transfer mechanisms; extracellular electron transfer; first derivative; fluorescence emission spectra; graphite interfaces; incubation periods; mediated electron transfer; oxidative potential; Shewanella; anodic oxidation; biofilms; chronoamperometry; cyclic voltammetry; electron transitions; emission spectroscopy; graphite; voltage regulators; graphite electrodes, quinone derivative; riboflavin; amperometry; bacterial growth; bacterial strain; bacterium culture; bioaccumulation; cell free system; cyclic potentiometry; electric current; electrochemistry; electrode; electron transport; fluorescence spectroscopy; incubation time; oxidation reduction potential; scanning electron microscopy; Shewanella loihica; supernatant
Academic Unit/Department: Mathematics, Computing and Technology > Engineering & Innovation
Item ID: 35403
Depositing User: Satheesh Krishnamurthy
Date Deposited: 16 Nov 2012 10:54
Last Modified: 16 Nov 2012 10:54
Share this page:


Scopus Citations

Actions (login may be required)

View Item
Report issue / request change

Policies | Disclaimer

© The Open University   + 44 (0)870 333 4340