Electrochemical reduction of oxygen catalyzed by a wide range of bacteria including Gram-positive

Abstract

Most bacteria known to be electrochemically active have been harvested in the anodic compartments of microbial fuel cells (MFCs) and are able to use electrodes as electron acceptors. The reverse phenomenon, i.e. using solid electrodes as electron donors, is not so widely studied. To our knowledge, most of the electrochemically active bacteria are Gram-negative. The present study implements a transitory electrochemical technique (cyclic voltammetry) to study the microbial catalysis of the electrochemicalreduction of oxygen. It is demonstrated that awiderange of aerobic and facultative anaerobic bacteria are able to catalyze oxygenreduction. Among these electroactive bacteria, several were Gram-positive. The transfer of electrons was direct since no activity was obtained with the filtrate. These findings, showing a widespread property among bacteriaincludingGram-positive ones, open new and interesting routes in the field of electroactive bacteria research.