Abstract
Polarized stainless steel cathodes in pure cultures of Geobacter sulfurreducens generated reduction currents of up to 30 A/m2 even when the sole electron acceptor contained in solution was completely reduced. It was shown here that these currents were driven by the carbon dioxide that was provided to the solution. It was postulated that CO2 reduction consumed succinate and produced glycerol, which remained stored inside the cells and was released under the effect of stress.