Sphingopyxis indica sp. nov., isolated from a high dose point hexachlorocyclohexane (HCH)-contaminated dumpsite

Abstract

A Gram-stain-negative, aerobic, non-motile, non-spore-forming, rod-shaped and light-yellow-pigmented bacterium, designated DS15(T), was isolated from a soil sample collected from a hexachlorocyclohexane dumpsite in Lucknow, Uttar Pradesh, India. Strain DS15(T) showed highest 16S rRNA gene sequence similarity to Sphingopyxis panaciterrulae DCY34(T) (98.7%) and Sphingopyxis soli BL03(T) (98.0%). The 16S rRNA gene sequence similarity between strain DS15(T) and species of genus Sphingopyxis with validly published names ranged from 92.5% to 98.7%. The DNA G+C content of strain DS15(T) was 67.5 mol%. The chemotaxonomic markers in strain DS15(T) were consistent with its classification in the genus Sphingopyxis, i.e. Q-10 as the major ubiquinone and summed feature 8 (C18:1ω7c/C18:1ω9c), C17:1ω6c, summed feature 3 (C16:1ω7c/C16:1ω6c), C14:0 2-OH, C15:0 2-OH, C16:0 and C17:1ω8c as the predominant fatty acids. The major polar lipids of strain DS15(T) were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylcholine (PC), phosphatidylglycerol (PG) and sphingoglycolipids (SGL) and spermidine was detected as the major polyamine. Phylogenetic analysis, DNA-DNA hybridization, and chemotaxonomic and phenotypic analysis support the conclusion that strain DS15(T) represents a novel species within the genus Sphingopyxis, for which the name Sphingopyxis indica is proposed. The type strain is DS15(T) (=MTCC 9455(T)=CCM 7542(T)=MCC 2023(T)).