Novosphingobium fontis sp. nov., isolated from a spring

Abstract

A bacterial strain designated STM-14T was isolated from a spring in Taiwan and characterized using a polyphasic taxonomic approach. Strain STM-14T was a Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, non-motile, rod-shaped bacterium and formed cream-coloured colonies. Strain STM-14T grew at 15-37 °C (optimum, 30 °C), at pH 5.0-9.0 (optimum, pH 6.0) and with 0-0.5 % (w/v) NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain STM-14T belonged to the genus Novosphingobium and showed the highest levels of sequence similarity to Novosphingobium naphthae D39T (98.5 %) and Novosphingobium mathurense SM117T (97.6 %). The major fatty acids (>10 %) of strain STM-14T were C17 : 1ω6c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω7c, C15 : 0 2-OH and C17 : 1ω8c. The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidyldimethylethanolamine, sphingoglycolipid, phosphatidylcholine and several uncharacterized lipids. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 66.6 mol%. The DNA-DNA hybridization value for strain STM-14T with N. naphthae JCM 31158T and N. mathurense DSM 23374T was less than 49 %. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain STM-14T should be classified as representing a novel species of the genus Novosphingobium, for which the name Novosphingobium fontis sp. nov. is proposed. The type strain is STM-14T (=BCRC 80924T=LMG 29290T=KCTC 42983T).