Potential and Cell Density Dependences of Extracellular Electron Transfer of Anode-Respiring Geobacter sulfurreducens Cells

Geobacter sulfurreducens has been extensively studied as a model electricity-producing microbes and it is now well known that extracellular electron transfer (EET) to an anode in this microbe is mediated through the expression of abundant outer membrane c-type cytochromes (OMCs). As the electrons need to travel across the biofilm formed on an anode, the macroscopic EET activity depends on the biofilm thickness. In this sense, it is worth investigating how the EET current depends on the optical cell density (OD) in the electrochemical chamber. Here we report that the OD value strongly affects on the relationship between the EET current and the anode potential. (C) The Electrochemical Society of Japan, All rights reserved.