Roseovarius spongiae sp. nov., a bacterium isolated from marine sponge

A taxonomic study was carried out on strain HN-E21 T , which was isolated from sponge collected from Yangpu Bay, Hainan, PR China. Cells of strain HN-E21 T were Gram-stain-negative, non-spore-forming, tumbling-motile, ovoid- to rod-shaped and pale-yellow-pigmented that could grow at 15-42 °C (optimum, 37 °C), at pH 6-11 (pH 7) and in 0-14 % (w/v) NaCl (2-3 %). This isolate was positive for oxidase and catalase, but negative for hydrolysis of aesculin and gelatin. The phylogenetic tree based on 16S rRNA gene sequences showed that strain HN-E21 T formed a clade with Pelagivirga sediminicola BH-SD19 T , Pontibaca methylaminivorans GRP21 T , Roseovarius antarcticus M-S13-148 T , Roseovarius aquimarinus CAU1059 T and Roseovarius nanhaiticus NH52J T within the family Rhodobacteraceae . Strain HN-E21 T shared the highest similarity to Pelagivirga sediminicola BH-SD19 T (95.5 %), followed by Roseovarius lutimaris 112 T (95.3 %), Pelagicola litorisediminis D1-W8 T (95.2 %), Roseovarius gaetbuli YM-20 T (95.0 %) and Roseovarius marisflavi H50 T (95.0 %). The dominant fatty acids were summed feature 8 (C 18 : 1 ω7 c and/or C 18 : 1 ω6 c ) and C 16:0. The major polar lipids comprised phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, three unidentified lipids and one unidentified phospholipid. The respiratory quinone was identified as Q-10. The G+C content of the genomic DNA was 66.4 mol%. Based on the phenotypic and phylogenetic data, strain HN-E21 T represents a novel species of the genus Roseovarius , for which the name Roseovarius spongiae sp. nov. is proposed, with the type strain HN-E21 T (=MCCC 1K03333 T =LMG 30456 T ).