Isolation and Characterization of an Electricity-producing Strain Shewanella sp. S2 from Marine

Abstract:

A new electrochemically active bacterium (exoelectrogen), strain S2, was isolated from coastal marine sediments of Xiamen. The phylogenetic trees based on 16S rRNA and gyrB gene sequences showed that strain S2 formed a lineage within the genus Shewanella and had high similarity (98.5% and 87.0%, respectively) with strain S. oneidensis MR-1. The phenotypic characteristics indicated strain S2 could be distinguished easily from S. oneidensis MR-1 by its culture conditions such as pH, NaCl tolerance and carbon source utilization. Based on these results, it is identified as Shewanella sp. S2. The preliminary current generation experiments showed that S2 could use lactate and xylose for electricity production. When lactate was used as a fuel, the MFC had highest voltage (150 mV) and current density (66.1 mA/m2).

Key words:Exoelectrogen, Shewanella, GyrB, Microbial fuel cell