Description of Sinobacter flavus gen. nov., sp. nov., and proposal of Sinobacteraceae fam. nov.

A novel Gram-negative, non-motile, rod-shaped bacterium, designated CW-KD 4(T), was isolated from a polluted soil sample collected from Jiangsu Province, China, by using a classic enrichment method. Based on 16S rRNA gene sequence analysis, the novel strain represented a deep-rooting lineage within the class Gammaproteobacteria that was clustered with the genera Hydrocarboniphaga and Nevskia and some other unidentified bacteria. Polyphasic taxonomic studies revealed that strain CW-KD 4(T) showed rather distant relationships to its phylogenetically closest neighbours, including the two recognized genera Hydrocarboniphaga and Nevskia. Strain CW-KD 4(T) showed only 89.9% and 89.7% 16S rRNA gene sequence similarities to the type species of the genera Hydrocarboniphaga and Nevskia, respectively. The predominant isoprenoid quinone of strain CW-KD 4(T) was Q-8 with minor components including Q-9, MK-7 and MK-6. The major fatty acids were C(16:0), C(18:1)omega7c and summed feature 3. The G+C content of the DNA was 65.1 mol%. On the basis of its distinctive phenotypic and genotypic characteristics, strain CW-KD 4(T) represents a new genus and a novel species in the class Gammaproteobacteria, for which the name Sinobacter flavus gen. nov., sp. nov. is proposed. The type strain is CW-KD 4(T) (=DSM 18980(T)=KCTC 12881(T)=CCTCC AB 206145(T)). In addition, a new family, Sinobacteraceae fam. nov., is proposed to house the genus Sinobacter gen. nov.