Sphingobacterium thermophilum sp. nov., of the phylum Bacteroidetes , isolated from compost

Abstract

A Gram-negative bacterium, designated CKTN2(T), was isolated from compost. Cells of strain CKTN2(T) were strictly aerobic rods. The isolate grew at 20-50 °C (optimum 40-45 °C), but not below 15 °C or above 52 °C, and at pH 5.9-8.8 (optimum pH 7.0), but not below pH 5.4 or above pH 9.3. The DNA G+C content was 40.3 mol%. The predominant menaquinone was MK-7. The major fatty acids were iso-C15 : 0 (45.2 %), iso-C17 : 0 3-OH (11.1 %) and C18 : 0 (14.5 %). Analysis of the 16S rRNA gene sequence of strain CKTN2(T) revealed that it is a member of the genus Sphingobacterium and is most closely related to Sphingobacterium alimentarium DSM 22362(T) (93.2 % 16S rRNA gene sequence similarity). Strain CKTN2(T) could be distinguished from its closest phylogenetic relatives by different phenotypic characteristics. According to the phenotypic and genotypic characteristics, strain CKTN2(T) represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium thermophilum sp. nov. is proposed. The type strain is CKTN2(T) ( = JCM 17858(T) = KCTC 23708(T)).