Determination of mass transport and kinetic properties of Geobacter sulfurreducens biofilms using a rotating disk electrode and numerical modeling

SEBASTIAN BONANNI; GERMÁN DAVID SCHROTT; DAVID J. SCHIFFRIN; JUAN PABLO BUSALMEN; DAN F. BRADLEY

Norwich

Congreso; Electron transfer at the microbe-mineral interface; 2012

Biochemical Society

Electroactive   bacteria   can   use   a   polarized   electrode   as  the  final   electron   acceptor  for  their respiratory   chain,   allowing   a   very   accurate   quantification   of  its   respiration   rate   by   the   use   of electrochemical   techniques.   The   rotating   disk   electrode  allows   straightforward   control   of   the mass   transport   rate   to   the  electrode  by   changing  its  rotating   speed,  and  is   one   of   the   few convective electrode systems for which hydrodynamic and convective-diffusion equations have been solved rigorously. In this work mathematical modeling of current produced by biofilms of Geobacter sulfurreducens grown on a rotating disk electrode, allowed the estimation of concentration profiles of substrate, protons,   buffer   and   current   density   within   the   biofilm   and   on   the   bulk   liquid,   under   different rotating speeds, substrate concentrations and pHs. Using this novel approach limiting factors for current     production    have     been    identified   under    different    operational     conditions    and     kinetic parameters for substrate consumption by Geobacter Sulfurreducens have been determined.