Sphingomonas histidinilytica sp. nov., isolated from a hexachlorocyclohexane dump site.

A Gram-negative, non-spore-forming, cream-coloured bacterial strain, UM2(T), was isolated from an open hexachlorocyclohexane (HCH) dump site at Ummari village in Lucknow, India. Data generated from a polyphasic approach including phenotypic, genotypic and chemotaxonomic analyses confirmed that strain UM2(T) belonged to the genus Sphingomonas. The highest similarity found to the 16S rRNA gene sequence of strain UM2(T) was 99.4 %, with Sphingomonas wittichii DSM 6014(T), whereas the DNA-DNA relatedness value between these strains was 31 %, indicating that they represent separate species. The DNA G+C content of UM2(T) was 66.9 mol%. The respiratory pigment ubiquinone Q-10 was present. The predominant fatty acids were summed feature 8 (C(18 : 1)omega6c and/or C(18 : 1)omega7c; 32.9 %), C(19 : 0) cyclo omega8c (15.5 %) and C(16 : 0) (12.1 %). The major polar lipids were phosphatidylcholine, phosphatidylglycerol and phosphatidyldimethylethanolamine. sym-Homospermidine was the major polyamine observed. On the basis of the data reported, it was concluded that UM2(T) represents a novel species of the genus Sphingomonas, for which the name Sphingomonas histidinilytica sp. nov. is proposed. The type strain is UM2(T) (=MTCC 9473(T) =CCM 7545(T)).