Tepidicella baoligensis sp. nov., A Novel Member of Betaproteobacterium Isolated from an Oil Reservoir

A Gram-negative, non-pigmented, aerobic bacterium, designated strain B18-50(T) was isolated from oil-well production water in Baolige oilfield, China. The strain was able to grow at pH 6.5-10.5 (optimum at pH 7.5-8.5), in 0-3% (w/v) NaCl (optimum at 0-0.5%, w/v) and at 20-60 degrees C (optimum at 45 degrees C). Cells of the isolate were motile with a single polar flagellum and non-spore-forming rods. Organic acids and amino acids were used as carbon and energy sources, but sugars and polyols were not assimilated. The major cellular fatty acids were C-16:0, C(16:1)6c/7c, and C(18:1)7c. Ubiquinone 8 was the predominant respiratory quinone. The major polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The genomic DNA G+C content of the isolate was 62.8mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain B18-50(T) was most closely related to Tepidicella xavieri DSM 19605(T) (97.5% similarity). Comparative analysis of genotypic and phenotypic features indicate that strain B18-50(T) represents a novel species of the genus Tepidicella, for which the name Tepidicella baoligensis sp. nov. is proposed. The type strain is B18-50(T) (=CGMCC 1.13575(T)=KCTC 62779(T)).