Response of antimicrobial nitrofurazone-degrading biocathode communities to different cathode potentials

Abstract

Bioelectrodegradation of various organic pollutants has been extensively studied. However, whether different cathode potentials could alter the antimicrobial-degrading biocathode community structure and composition remain poorly understood. Here, the microbial community structure and composition of the nitrofurans nitrofurazone (NFZ) degrading biocathode in response to different cathode potentials (-0.45±0.01, -0.65±0.01 and -0.86±0.05V vs standard hydrogen electrode, with applied cell voltages of 0.2, 0.5 and 0.8V, respectively) were investigated. The bioelectrodegradation efficiency and degree of NFZ were highly related to different cathode potentials. The 0.2 and 0.5V performed biocathode communities were similar but significantly differed from those of the 0.8V and open circuit biofilms. The bacteria possessing functions of nitroaromatics reduction and electrons transfer (e.g. Klebsiella, Enterococcus, Citrobacter and Desulfovibrio) were selectively enriched in different biocathode communities. This study offers new insights into the ecological response of antimicrobial-degrading biocathode communities to different cathode potentials.

Keywords: Biocathode community structure; Cathode potential regulation; NFZ bioelectrodegradation; Nitrofurans nitrofurazone (NFZ).