Dokdonia sinensis sp. nov., a flavobacterium isolated from surface seawater

A taxonomic study was carried out on strain SH27(T), which was isolated from seawater collected around Xiaoshi Island, PR China. Cells of strain SH27(T) were Gram-stain-negative, non-motile, rod-shaped, orange-pigmented and grew at 15-37 degrees C (optimum, 28 degrees C), at pH 6.0-8.0 (pH 7.0) and in 1.0-7.0 % (w/v) NaCl (2.0-3.0 %). The isolate was positive for catalase, but negative for nitrate reduction, oxidase, indole production and urease. Carotenoid pigment was produced. Phylogenetic analysis based on the 16S rRNA gene placed strain SH27(T) in the genus Dokdonia with the closest relative being Dokdonia donghaensis KCTC 12391(T), exhibiting 96.7 % 16S rRNA gene pairwise similarity. The results of genomic comparisons, including average nucleotide identity and digital DNA-DNA hybridization, showed 72.9 and 19.2 % identity to D. donghaensis KCTC 12391(T), respectively. The major cellular fatty acids were iso-C-15:0, iso-C(15:1 )G and iso-C(17.0 )3-OH. The major polar lipids were phosphatidylethanolamine and two unidentified lipids. Menaquinone-6 was the only respiratory quinone. The G+C content of the genomic DNA was 32.9 mol%. On the basis of the phenotypic and phylogenetic data, strain SH27(T) represents a novel species of the genus Dokdonia, for which the name Dokdonia sinensis sp. nov. is proposed, with the type strain SH27(T) (MCCC 1H00358(T)=CCTCC AB 2018323(T)=KCTC 62962(T)).