Development of Microbial Fuel Cells Utilizing Glycerol as a Sole Carbon Source

A microbial fuel cell (MFC) system to generate electric power from glycerol, a by-product generated in the production process of biodiesel, was developed using microbes utilizing glycerol as a carbon source. Microorganisms utilizing glycerol as a sole carbon source were isolated from the soil and waterfront environments. Finally, five microbes which were able to grow up in the medium containing 10 % glycerol were obtained and examined to generate electric power from glycerol in our MFC system. Three of the five microbes showed electric power generation. Especially, Isolate 1 showed the greatest values of maximum power output, 0.102 mW/cm2, in the presence of 2-hydroxy-1,4-naphoquinone as a mediator. Isolate 1 showed higher maximum power value when using glycerin as a substrate than glucose, suggesting that electron transfer to the electrode by the mediator is a rate limiting step of MFC performance rather than substrate degradation.