Sphingobium lucknowense sp. nov., a hexachlorocyclohexane (HCH)-degrading bacterium isolated from HCH-contaminated soil

Abstract

A yellow-pigmented, hexachlorocyclohexane (HCH)-degrading bacterium, designated F2T, was isolated from an HCH dumpsite at Ummari village in Lucknow, India. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belonged to the genus Sphingobium. Its closest neighbour was Sphingobium japonicum UT26T (99.2 % 16S rRNA gene sequence similarity). The DNA G+C content was 65.7 mol%. The polyamine profile showed the presence of spermidine. The respiratory pigment was ubiquinone Q-10. The predominant cellular fatty acids were C16 : 0 (12.5 %), C14 : 0 2-OH (8.1 %), summed feature 3 (consisting of C16 : 1ω7c and/or C16 : 1ω6c; 5.8 %) and summed feature 8 (consisting of C18 : 1ω7c and/or C18 : 1ω6c; 53.1 %). The major polar lipids of strain F2T were phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and sphingoglycolipid. DNA–DNA relatedness and biochemical and physiological characters clearly distinguished the isolate from its closest phylogenetic neighbours. Thus, strain F2T represents a novel species of the genus Sphingobium, for which the name Sphingobium lucknowense sp. nov. is proposed. The type strain is strain F2T ( = MTCC 9456T  = CCM 7544T).