Towards the understanding of the effect of oxygen on the electrocatalytic activity of microbial biofilms: a spectroelectrochemical study

Abstract

Under anoxic conditions, microbial biofilms of metal-respiring bacteria grown on electrodes oxidize an organic substrate and generate electrocatalytic currents. Exposing the biofilm to molecular oxygen suppresses the electrocatalytic current completely. Chronoamperometry and resonance Raman scattering performed simultaneously on the same mixed culture biofilm show that current suppression is caused by the rapid oxygen-induced oxidation of the outer membrane cytochromes wiring the cell metabolism to the electrode.