Abstract
Geobacter species are dissimilatory iron-reducing deltaproteobacteria (DIRD) that have various capabilities for bioremediation and microbial fuel cells, including, but not limited to, dissimilatory iron reduction. Furthermore, novel DIRD have been isolated and studied worldwide. However, these bacteria have not been isolated in Japan. In this study, we attempted to develop a rapid detection method of DIRD by real-time PCR and melting curve analysis to make DIRD detection more efficient. Sediments samples were collected from four sites of the Tomoe River and one of its tributaries in the urban area of Shizuoka City, Japan. When sediments from all the sites were incubated in a ferrihydrite-enriched medium, the medium turned black after 14 days of incubation and showed a magnetic response, indicating the presence of DIRD. Denaturing gradient gel electrophoresis profiles of the samples after incubation revealed that species closely related to Geobacter sulfurreducens PCA exist in all the samples. Furthermore, we found a species closely related to Desulfuromonas alkaliphilus Z-0531 in the midstream sample of the Tomoe River. Consequently, we succeeded in detecting DIRD in all the samples by melting curve analysis without ferrihydrite-enriched cultures.
