Sphingobium terrigena sp. nov., isolated from gasoline-contaminated soil

Abstract

A Gram-stain-negative, strictly aerobic bacterial strain, designated E09(T), was isolated from gasoline-contaminated soil in the Republic of Korea. Cells were non-motile short rods showing catalase- and oxidase-positive reactions. Growth was observed at 10-37 degrees C (optimum, 30 degrees C), at pH 6.0-9.0 (pH 6.5) and in the presence of 0-0.5 % (w/v) NaCl (0 %). Ubiquinone-10 (Q-10) and spermidine were identified as the predominant respiratory quinone and polyamine, respectively. Summed feature 8 (comprising C-18(:1)omega 7c/C-18(:1)omega 6c), summed feature 3 (comprising C-16(:1)omega 7c/C-16(:1)omega 6c), C-16(:0) and C-14(:0) 2-OH were identified as major cellular fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid, phosphatidylglycerol and an unidentified phospholipid. The G+C content of the genomic DNA was 62.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain E09(T) formed a tight phylogenetic lineage with Sphingobium xenophagum NBRC 107872(T) and Sphingobium hydrophobicum C1(T) within the genus Sphingobium. Strain E09(T) was most closely related to S. xenophagum NBRC 107872(T) (97.2 %) and S. hydrophobicum C1(T) (97.2 %), but DNA-DNA relatedness levels between strain E09(T) and the type strains of S. xenophagum and S. hydrophobicum were 37.1 and 36.8 % , respectively. Based on its phenotypic, chemotaxonomic and molecular features, strain E09(T) clearly represents a novel species of the genus Sphingobium, for which the name Sphingobium terrigena sp. nov. is proposed. The type strain is E09(T) (=KACC 19523(T) =JCM 32762(T)).