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

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

Norwich

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

Biochemical Society of the United Kingdom

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. It is also one of the few convective electrode systems for which hydrodynamic and convective-diffusion equations have been solved rigorously, which is essential for modeling the system.In this work numerical 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.