Phreatobacter cathodiphilus sp nov., isolated from a cathode of a microbial fuel cell

A novel bacterial strain, S-12(T), of a member of the genus Phreatobacter was isolated from a cathode of a microbial fuel cell from Suwon City, South Korea. Cells were Gram-staining-negative, aerobic, non-sporulating rods, motile by means of a polar flagellum, and formed white round colonies. The strain grew at the range of 10-40 degrees C (optimum, 28-30 degrees C), pH 6.0-10.0 (optimum 7.0-8.0) and 0-1% NaCl. The 16S rRNA gene sequence analysis showed the relatedness of S-12(T) to Phreatobacter stygius YC6-17(T) (98.2 %) and Phreatobacter oligotrophus PI_21(T)(98.1 %). The major respiratory quinone was ubiquinone Q-10. Polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified lipid. The major fatty acids were summed feature 8 (C-18 : 1 omega 7c and/ or C-18 : 1 omega 6c). The DNA G+C content was 69.3 mol%. On the basis of its differences from species of the genus Phreatobacter with validly published names, strain S-12(T) is identified as representing a novel species, for which the proposed name is Phreatobacter cathodiphilus sp. nov., with S-12(T) as the type strain (=KACC 18497(T)=JCM 31612(T)).