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

Abstract

A yellow-pigmented, hexachlorocyclohexane (HCH)-degrading bacterium, designated F2(T), 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 UT26(T) (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 C(16:0) (12.5%), C(14:0) 2-OH (8.1%), summed feature 3 (consisting of C(16:1)ω7c and/or C(16:1)ω6c; 5.8%) and summed feature 8 (consisting of C(18:1)ω7c and/or C(18:1)ω6c; 53.1%). The major polar lipids of strain F2(T) 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 F2(T) represents a novel species of the genus Sphingobium, for which the name Sphingobium lucknowense sp. nov. is proposed. The type strain is strain F2(T) (=MTCC 9456(T) =CCM 7544(T)).