title: Contribution of direct electron transfer mechanisms to overall electron transfer in microbial fuel cells utilising Shewanella oneidensis as biocatalyst.
abstract: OBJECTIVE
  To investigate the contribution of direct electron transfer mechanisms to electricity production in microbial fuel cells by physically retaining Shewanella oneidensis cells close to or away from the anode electrode.
  
  
  RESULTS
  A maximum power output of 114 ± 6 mWm(-2) was obtained when cells were retained close to the anode using a dialysis membrane. This was 3.5 times more than when the cells were separated away from the anode. Without the membrane the maximum power output was 129 ± 6 mWm(-2). The direct mechanisms of electron transfer contributed significantly to overall electron transfer from S. oneidensis to electrodes, a result that was corroborated by another experiment where S. oneidensis cells were entrapped in alginate gels.
  
  
  CONCLUSIONS
  S. oneidensis transfers electrons primarily by direct electron transfer as opposed to mediated electron transfer.
authors.affiliation: Department of Life Sciences, Faculty of Science and Technology, University of Westminster, 115 New Cavendish Street, London, W1W 6UW, UK.
authors.forename: Segun
authors.initials: S
authors.lastname: Fapetu
authors.affiliation: Department of Life Sciences, Faculty of Science and Technology, University of Westminster, 115 New Cavendish Street, London, W1W 6UW, UK.
authors.forename: Taj
authors.initials: T
authors.lastname: Keshavarz
authors.affiliation: University of Lincoln College of Science, Brayford Pool, Lincolnshire, LN6 7TS, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Clements
authors.affiliation: Department of Life Sciences, Faculty of Science and Technology, University of Westminster, 115 New Cavendish Street, London, W1W 6UW, UK. g.kyazze@westminster.ac.uk.
authors.forename: Godfrey
authors.initials: G
authors.lastname: Kyazze
mesh_terms: D001674:Bioelectric Energy Sources / Q000382:microbiology*; D004579:Electron Transport / Q000502:physiology; D020592:Shewanella / Q000378:metabolism*
keywords: Cell immobilisation; Dialysis membrane; Direct electron transfer; Extracellular electron transfer; Mediated electron transfer; Microbial fuel cell; Shewanella oneidensis