A new electrochemically active bacterium phylogenetically related to Tolumonas osonensis and power performance in MFCs

A facultative anaerobic bacterium (designated as P2-A-1) was isolated from microbial fuel cells (MFCs) inoculated with sludge from a sewage treatment plant. Based on 16S rDNA sequence analysis, the strain was identified as Tolumonas osonensis OCF 7T according to its biochemical, physiological and morphological characteristics. Through parameters optimization, the P2-A-1 MFC reached the maximum power density of 424 mW/m2 in the substrate of 2 g/L sodium acetate. Further, a facile bacteria treatment approach by chemically “perforating” pores and channels on bacterial membrane was developed to significantly improve the power density. And 1 mM of EDTA-treated cell yielded the highest power density of 509.1 mW/m2 because the membrane permeability of cell was enhanced by verification of coenzyme Q and fatty acid composition tests. It offers a novel facultative anaerobic Gram-positive bacterium that can utilize a wide variety of substrates for power production, making it highly valuable for application in MFCs.