Systematic investigation of anode materials for microbial fuel cells with the model organism G. sulfurreducens

Different carbon and metal-based anode materials for microbial fuel cells were systematically investigated with a pure culture of the model organism G. sulfurreducens. The highest limiting current density of 756 ± 15 μA cm−2 at −0.253 ± 0.037 V vs. SCE was achieved with graphite foil using a step-wise galvanostatic technique. But also the application of completely different anode materials such as activated carbon cloth, stainless steel and graphite felt led to similar high limiting current densities, suggesting that G. sulfurreducens is able to use a large range of substantially different anode materials as external electron acceptor. Additionally, we could show that a step-wise galvanostatic technique to record polarization curves yields similar current densities as potentiostatic control at −0.400 V vs. SCE with the investigated carbon-based materials. In case of stainless steel these techniques yield slightly different results, presumably due to an effect related to the material's surface properties.