Comparative study on the metabolic behaviour of anode biofilm in microbial fuel cell under different external resistance

Abstract

Abstract In this study the influence of the external circuit resistance on the metabolic behaviour of anodic biofilm in Microbial fuel cell (MFC) was studied. The results obtained demonstrated that extremely low and extremely high circuit loads could deteriorate the bio-electrochemistry of anodic respiration by shifting the microbial metabolism towards typical fermentation of the substrates. The best conditions for respiration and efficient substrate mineralisation of nearly 70% were found in the MFC reactor with 0.1 kΩ resistance in the anode and cathode connecting circuit. Two species of electrochemically active bacteria were isolated from the anodic community and were taxonomically affiliated to Pseudomonas and Bacillus genera based on 16 s rRNA genes amplification and sequencing.