Ostreibacterium oceani gen. nov., sp. nov., isolated from oyster, and description of Ostreibacteriaceae fam. nov.

A novel Gram-stain-negative, short rod-shaped, facultatively anaerobic, non-motile, non-gliding, oxidase-positive and catalase-negative bacterium, designated ML27 T , was isolated from oyster homogenate in Rushan, Weihai, PR China. Growth occurred at 20–33 °C (optimum, 30 °C), at pH 7.0–9.0 (optimum, pH 7.5–8.0) and in the presence of 1–6 % (w/v) NaCl (optimum, 3 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ML27 T was 90.7 % similar to Suttonella ornithocola DSM 18249 T , 89.2 % to Suttonella indologenes JCM 1478 T and 88.2 % to Cardiobacterium hominis DSM 8339 T ; similarities to other species were less than 90 %. The average amino acid identity between strain ML27 T , S. indologenes JCM 1478 T , S. ornithocola DSM 18249 T , C. hominis DSM 8339 T and Dichelobacter nodosus ATCC 25549 T were 46.23, 45.86, 45.54 and 45.84 %, respectively. Phylogenomic tree and phylogenetic analyses based on 16S rRNA gene sequences showed that the isolate formed a novel family-level clade in the order Cardiobacteriales . The sole respiratory quinone was ubiquinone-7 (Q-7). The dominant cellular fatty acids were summed feature 8 (C 18 : 1 ω7 c /C 18 : 1 ω6 c ; 46.3 %), C 16 : 0 (17.8 %) and summed feature 3 (C 16 : 1 ω7 c /C 16 : 1 ω6 c ; 13.5 %). The DNA G+C content of strain ML27 T was 45.6 mol%. Polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and one unidentified lipid. Comparative analyses of 16S rRNA gene sequences, genomic distinctiveness and characterization indicated that strain ML27 T represents a novel species of a new genus within a novel family of the order Cardiobacteriales , for which the name Ostreibacterium oceani gen. nov., sp. nov. is proposed. The type strain of Ostreibacterium oceani is ML27 T (=MCCC 1H00372 T =KCTC 72155 T ). In addition, a novel family, Ostreibacteriaceae fam. nov., is proposed to accommodate the genus Ostreibacterium .