Microbial electrosynthesis on stainless steel electrodes by a homoacetogenic community: are carbon electrodes needed?

In this work three observations are reported leading to a reconsideration of biofilm based microbial electrosynthesis (MES). The first is that stainless steel felt cathodes are able to support MES from CO2 to volatile fatty acids. The second is that biomass is efficiently trapped as a biofilm and in flocs between the stainless steel fibres, possibly enabling higher electron conversion rates due to high hydrogen partial pressures close to the biocatalysts. A third observation is transient formate production during MES of acetate. These three key findings offer a different perspective on MES i.e. challenging the biofilm paradigm. Is a biofilm really needed to achieve profitable MES