Roseovarius azorensis sp. nov., isolated from seawater at Espalamaca, Azores

A Gram-negative, motile, non-spore forming, rod shaped aerobic bacterium, designated strain SSW084T, was isolated from a surface seawater sample collected at Espalamaca (38°33′N; 28°39′W), Azores. Growth was found to occur from 15 to 40 °C (optimum 30 °C), at pH 7.0–9.0 (optimum pH 7.0) and with 25–100 % seawater or 0.5–7.0 % NaCl in the presence of Mg2+ and Ca2+; no growth was found with NaCl alone. Colonies on seawater nutrient agar were observed to be punctiform, white, convex, circular, smooth, and translucent. Strain SSW084T did not grow on Zobell marine agar and tryptic soy agar even when seawater supplemented. The major respiratory quinone was found to be Q-10 and the G + C content was determined to be 61.9 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain SSW084T belongs to the genus Roseovarius and that its closest neighbours are Roseovarius tolerans EL-172T, Roseovarius mucosus DFL-24T and Roseovarius lutimaris 112T with 95.7, 95.4 and 95.3 % sequence similarity respectively. The remaining species of Roseovarius showed <95 % similarity. The polar lipids of strain SSW084T were determined to be phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, an unidentified lipid and one unidentified aminolipid. The major fatty acids identified were identified as C18:1 ω7c (52.5 %) and C16:0 (13.8 %). On the basis of phenotypic, molecular and chemotaxonomic characteristics, strain SSW084T is considered to represent a novel species of the genus Roseovarius, for which Roseovarius azorensis sp. nov is proposed. The type strain is SSW084T (=KCTC 32421T = MTCC 11812T).