Pelagibacterium xiamenense sp. nov., isolated from intertidal sediment

A Gram-stain-negative, obligately aerobic bacterium, designated as HS1C4-1(T), was isolated from a sediment sample from the tidal zone of the Haicang Coast, Xiamen, Fujian Province, PR China. The strain was yellowish-coloured, non-gliding, rod-shaped and motile, with a single polar flagellum. Cells of HS1C4-1(T) were oxidase- and catalase-positive. The strain could grow at 15-55 degrees C (optimum 37 degrees C), pH 6.0-10.0 (optimum, pH 7.0-9.0), in the presence of 0-12 % (optimum, 1 %) NaCl (w/v). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that HS1C4-1(T) represented a member of the genus Pelagibacterium, and shared the highest similarity to Pelagibacterium luteolum CGMCC 1.10267(T) (97.6 %). Digital DNA-DNA hybridization values and average nucleotide identity between HS1C4-1(T) and all the species of genus Pelagibacterium were 18.7-20.2 % and 77.3-78.4 %, respectively. The principal fatty acids (>10 %) were C-19:0 cyclo omega 8c (50.5 %) and summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c; 29.1%). Q-10 was the sole respiratory quinone. The polar lipids included diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids and six unidentified lipids. The G+C content of the chromosomal DNA was 62.9 %. On the basis of phylogenetic, phenotypic, chemotaxonomic and genomic characteristics, HS1C4-1(T) represents a novel species within the genus Pelagibacterium, for which the name Pelagibacterium xiamenense sp. nov. is proposed. The type strain is HS1C4-1(T) (=MCCC 1A18759(T)=KCTC 92097(T)).