Roseibium aestuarii sp. nov., isolated from Pearl River Estuary.

A novel bacterium, designated strain SYSU M00256-3T, was isolated from a water sample collected from Pearl River Estuary at Guangzhou, PR China. Its taxonomic position was determined by using a polyphasic approach. Cells of the strain were Gram-staining-negative, motile, aerobic and rod-shaped with peritrichous flagella. It could grow at 15-45 °C, pH 4.0-10.0 and in the presence of 0-7.5 % (w/v) NaCl. The chemotaxonomic features of strain SYSU M00256-3T included ubiquinone-10 (Q-10) as the sole respiratory quinone; phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid as major polar lipids; summed feature 8 (C18 : 1  ω7c and C18 : 1  ω6c) as the predominant fatty acids (>70 %). On the basis of 16S rRNA gene sequence analysis, strain SYSU M00256-3T was most closely related to the type strains of Roseibium hamelinense CGMCC 1.12584T (97.7 %) and R. aquae CGMCC 1.12426T (97.2 %), R. sediminis KCTC 52373T (96.7 %), R. denhamense CGMCC 1.12583T (96.4 %). The average nucleotide identity (ANI) values between R. aestuarii SYSU M00256-3T and R. hamelinense CGMCC 1.12584T, R. aquae CGMCC 1.12426T, R. denhamense CGMCC 1.12583T and R. sediminis KCTC 52373T were 78.0, 78.2, 77.7 and 78.8, and the dDDH value is 20.0, 20.8, 20.1 and 20.6 correspondingly. Based on the analyses of the phenotypic, genotypic and phylogenetic characteristics, strain SYSU M00256-3T is characterized to represent a novel species of the genus Roseibium, for which the name Roseibium aestuarii sp. nov. is proposed. The type strain is SYSU M00256-3T (=NBRC 112946T=CGMCC 1.16156T).