Sphingobium chinhatense sp. nov., a hexachlorocyclohexane (HCH)-degrading bacterium isolated from an HCH dumpsite.

A yellow-pigmented, hexachlorocyclohexane (HCH)-degrading bacterium, strain IP26(T), was isolated from an HCH dumpsite and subjected to a polyphasic analysis in order to determine its taxonomic position. Strain IP26(T) showed maximum 16S rRNA gene sequence similarity with Sphingobium francense Sp+(T) (98.5 %), Sphingobium japonicum UT26(T) (98.4 %) and Sphingobium indicum B90A(T) (98.2 %). Phylogenetic analysis based on 16S rRNA gene sequences also showed that strain IP26(T) formed a cluster with these three HCH-degrading strains. Chemotaxonomic data (major polyamine, spermidine; major quinone, ubiquinone with ten isoprene units; major polar lipids, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, diphosphatidylglycerol, phosphotidylcholine; and presence of 2-hydroxy fatty acid) supported inclusion of strain IP26(T) in the genus Sphingobium. However, the results of DNA-DNA hybridization and morphological and biochemical tests clearly allowed phenotypic and genotypic differentiation of strain IP26(T) from recognized species of the genus Sphingobium. Strain IP26(T) thus represents a novel species of the genus Sphingobium for which the name Sphingobium chinhatense sp. nov. is proposed. The type strain is IP26(T) (=MTCC8598(T) =CCM 7432(T)).