A Gram-stain-negative, rod-shaped, non-motile and facultatively anaerobic bacterium, designated AM505T, was isolated from Shuangdao Bay in Weihai, China. Cells of strain AM505T were 0.4-0.8 µm wide, 1.3-3.3 µm long, catalase-positive and oxidase-positive. Strain AM505T was tolerant to moderate salt conditions. Growth occurred at 4-40 °C (optimum, 28-33 °C), pH 6.5-9.5 (pH 7.5-8.0) and with 0.5-9.0 % NaCl (w/v; 2.0-4.0 %). A phylogenetic analysis of the 16S rRNA gene indicated that strain AM505T was a member of the genus Pararhodobacter within the family Rhodobacteraceae. The most closely related neighbour was Pararhodobacter aggregans DSM 18938T (97.6 %). The average nucleotide identity value between AM505T and P. aggregans DSM 18938T was 75.3 %. The major respiratory quinone of strain AM505T was ubiquinone-10 and the predominant cellular fatty acids (>10 %) were summed feature 8 (consisting of C18 : 1ω7c and/or C18 : 1ω6c), 11-methyl C18 : 1ω7c and C18 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified aminolipid. The genomic DNA G+C content was 63.0 mol%. Based on our polyphasic taxonomic study, strain AM505T should be a novel species in the genus Pararhodobacter, for which the name Pararhodobacteroceanensis sp. nov. is proposed. The type strain is AM505T (=KCTC 62407T=MCCC 1H00289T).
Keywords: Pararhodobacter; Rhodobacteraceae; polyphasic taxonomy.