Sphingobacterium humi sp. nov., isolated from soil.

ABSTRACT

A Gram-stain-negative, facultatively aerobic bacterium, designated strain D1T, was isolated from soil in South Korea. Cells of strain D1T were non-motile rods with oxidase- and catalase-positive activities. Growth was observed at 15-40 °C (optimum, 30-37 °C), at pH 5.5-9.0 (optimum, pH 7.0-8.0) and in the presence of 0.0-5.0 % (w/v) NaCl (optimum, 0.0-1.0 %). The only respiratory quinone detected was menaquinone 7 (MK-7), and iso-C15  0, iso-C17  0 3-OH and summed feature 3 (comprising C16  1ω7c/C16  1ω6c) were identified as the major fatty acids. Phosphatidylethanolamine was the major polar lipid, and two unidentified glycophospholipids and four unidentified lipids were also detected as minor polar lipids. Sphingolipids, a typical chemotaxonomic feature of the genus Sphingobacterium, were detected. The G+C content of the genomic DNA was 43.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain D1T formed a phyletic lineage with Sphingobacterium hotanense XH4T within the genus Sphingobacterium. Strain D1T was most closely related to S. hotanense XH4T (98.1 % 16S rRNA gene sequence similarity) and Sphingobacterium cellulitidis R-53603T (97.2 %), and the DNA-DNA relatedness level between strain D1T and the type strain of S. cellulitidis was 43.1±0.7 %. Based on the phenotypic, chemotaxonomic and molecular features, strain D1T clearly represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium humi sp. nov. is proposed. The type strain is D1T (=KACC 18595T=JCM 31225T).