Novosphingobium aureum sp. nov., a marine bacterium isolated from salt flat sediment

Abstract

A Gram-stain-negative, aerobic, pale yellow-coloured, rod-shaped marine bacterium designated strain YJ-S2-02^T was isolated from salt flat sediment sampled in Yongyu-do, Republic of Korea. Strain YJ-S2-02^T grew at pH 6.0-9.0 (optimum, pH 7.0), 10-40 °C (optimum, 30 °C) and with optimum 1 % (w/v) NaCl. The 16S rRNA gene sequence analysis indicated that strain YJ-S2-02^T was closely related to Novosphingobium naphthalenivorans NBRC 102051^T (97.8 %) followed by Novosphingobium mathurense SM117^T (97.5 %), Novosphingobium indicum H25^T (97.3 %), Novosphingobium pentaromativorans US6-1^T (96.8 %), Novosphingobium fontis STM-14^T (96.6 %), Novosphingobium endophyticum EGI60015^T (96.5 %), Novosphingobium naphthae D39^T (96.5 %) and Novosphingobium malaysiense MUSC 273^T (95.9 %). The average nucleotide identity and estimated DNA-DNA hybridization values between YJ-S2-02^T and related type strains were 77.0-77.9 % and 19.1-24.0 %. Strain YJ-S2-02^T was characterized as having Q-10 as the predominant respiratory quinone and the principal fatty acids (>10 %) were summed feature 8 (C_{18 : 1} ω6c/ω7c, 20.7 %), C_{18 : 3} ω6c (16.3 %) and C_{17 : 1} ω6c (11.8 %). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, sphingolipids and two unidentified lipids. The DNA G+C content of strain YJ-S2-02^T was 65.6 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, YJ-S2-02^T should be classified as representing a novel species within the genus Novosphingobium, for which name Novosphingobium aureum is proposed, with the type strain YJ-S2-02^T (=KACC 21677^T =KCTC 72891^T=JCM 33996^T).

Keywords: Novosphingobium; Sphingomonadaceae; marine bacteria; salt flat.