Novel Geobacter Strain

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Technology Geobacter species have the ability to completely oxidize organic substrates to CO2 while utilizing an anode as the sole electron acceptor. This capability is shared by only a few other pure cultures. UMass microbiologist Derek Lovley and his colleagues have developed a novel Geobacter strain "Neo" that has been specifically adapted to a fuel cell environment. By maintaining a high selection pressure in the microbes- environment, the original wild type strain was coerced to adapt by developing new characteristics. Geobacter sulfurreducens is considered to be a leading candidate for use in microbial fuel cells. Geobacter clearly outperforms organisms such as Shewanella and Rhodopherax in growth characteristics and the ability to produce electric current. However, Geobacter-based microbial fuel cells still do not produce sufficient powder densities for practical applications. Several research groups, such as Hy-SyEnce, a Dartmouth, MA start-up company, are developing microbial fuel cells based on indigenous mixed microbial communities. While it has been noticed that mixed cultures produce higher power densities than pure cultures in fuel cells, new research suggests that this is likely due to differences in the fuel cell design (refer to attached research publication by Nevin et al, "Power output and columbic efficiencies from biofilms of Geobacter sulfurreducens comparable to mixed community microbial fuel cells" in Environmental Microbiology; please note that the experiments in this study were performed using the wild-type strain of G. sulfurreducens). Mixed cell cultures are much harder to optimize, scale-up and manipulate than pure cultures are, thereby making the development of a pure culture based microbial fuel cell important.