Roseobacter sinensis sp. nov., a marine bacterium capable to synthesize arachidonic acid

Strain WL0113^T was isolated from surface seawater of the coast of Lianyungang, Jiangsu province, PR China. Strain WL0113^T shared highest 16S rRNA gene sequence similarity with Roseobacter insulae YSTF-M11^T (98.8%), followed by R. cerasinus AI77^T (98.8%), R. ponti MM-7 ^T (98.0%). Strain WL0113^T was Gram-stain-negative, cream, aerobic, non-motile and coccoid- to oval-shaped, and able to grow at pH 6.5–9.0 (optimum, pH 7.0–8.0), at 10–37  °C (optimum, 28 °C) and in the presence of 1–5% (w/v; optimum, 2.5%) NaCl. Ubiquinone-10 was detected as dominant. The main fatty acids (> 5%) of the strain WL0113^T were C_16:0, iso-C_17:0 3OH, C_20:4ω6,9,12,15c (arachidonic acid), and summed feature 8 (C_18:1ω7c and/or C_18:1ω6c). The major polar lipids include phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, glycophospholipid, unknown aminolipid, unknown phospholipid, and two unknown polar lipids. The ANI and dDDH values between strain WL0113^T and Roseobacter cerasinus were 80.4% and 23.0%, respectively. The genomic DNA G + C content of strain WL0113^T was 63.1%. Based on these data, it is proposed that strain WL0113^T represent novel species of the genus Roseobacter, for which the name Roseobacter sinensis sp. nov. is proposed. The type strain is WL0113^T (= GDMCC 1.3082^T = JCM 35567^T).