Bacterial communities on electron-beam Pt-deposited electrodes in a mediator-less microbial fuel cell

The content of a bacterial consortium found on an electron beam (e-beam) Pt-deposited electrode in a mediator-less microbial fuel cell (MFC) using glucose and glutamate as fuel is reported in this paper. The e-beam Pt-deposited electrode and electrochemically active bacteria (EAB) consortium were developed to improve the mediator-less MFC performance. Denaturing gradient gel electrophoresis (DGGE), restriction fragment length polymorphism (RFLP), and 16S rRNA sequencing were used to identify the EAB consortia. Sequencing results showed that clone ASP-31 was predominant and was similar to Aeromonas hydrophila, an Fe(III)-reducing and EAB. The phylogenetic tree analysis disclosed the presence of gamma-proteobacteria groups such as Aeromonas genus, Enterobacter asburiae, and Klebsiella oxytoca. These results suggest that MFC performance of the e-beam Pt-deposited electrode with Aeromonas genus consortia dominated by A. hydrophila was higher than other MFCs within a short period. With the e-beam Pt-deposited electrode and Aeromonas genus consortia in the mediator-less MFC, it is possible to increase the efficiency of electron transfer between the bacteria and the electrode.