Abstract:[Background] Biocathode microbial fuel cell is a promising wastewater treatment system due to its low construction cost and sustainable development of the cathode. However, the oxidation-reduction properties of cathode microorganisms limit its further development in practical applications. [Objective] In order to improve the performance of the biocathode, it is necessary to understand the microbial community that affects the redox performance of the cathode. [Methods] The 16S rRNA gene high-throughput sequencing technology was used to analyze and compare the microbial diversity and structural changes of the original inoculated sludge samples and the domesticated cathode electrode biofilm samples. [Results] The sequencing results showed that there were significant differences in the types and structures of microbial communities in the original inoculated sludge and the domesticated cathode electrode biofilm samples. The relative abundance ratios of Proteobacteria, Gammaproteobacteria and Trueperaceae in the cathodic electrode biofilm samples after domestication were higher than those of the original sludge samples, which became the dominant flora. [Conclusion] Domestication has a significant impact on the biofilm community of the cathode electrode of the system. With the output of electricity production, the dominant bacterial community is continuously enriched, and finally a new microbial community adapted to the experimental environment is formed. Discussing the structure and changes of the dominant flora, which provide more biological theoretical foundations for the research of biocathode.
