Roseibium algae sp. nov., isolated from a marine alga (Grateloupia sp.)

A novel Gram-stain-negative, rod-shaped, non-spore-forming, aerobic, motile bacterium with a single polar or subpolar flagellum, designated strain H3510^T, was isolated from marine alga collected on sea shore of Yantai, PR China. The organism grew optimally at 28 °C and pH 7.0 and in presence of 3.0 % (w/v) NaCl. The strain exhibited positive catalase activity but negative oxidase and nitrate reduction activities. The predominant cellular fatty acids were C_18 : 1  ω7c and/or C_18 : 1  ω6c, 11-methyl C_18 : 1  ω7c, and C_16 : 0. Additionally, the major polar lipids were phosphatidylglycerol, phosphatidylmonomethylethanolamine, diphosphatidylglycerol, and phosphatidylethanolamine; the respiratory quinone was ubiquinone 10 (Q-10). The genomic DNA G+C content of strain H3510^T was 54.2%. The novel strain showed the closest relationship with Roseibium polysiphoniae KMM 9699^T with 98.2 % 16S rRNA gene sequence similarity. The calculated values for average nucleotide identity and DNA-DNA hybridization between strain H3510^T and the phylogenetically related Roseibium species were in the range of 71.3-74.9 % and 13.7-19.9 %, respectively. Based on polyphasic analyses, strain H3510^T was identified as representing a novel species of the genus Roseibium, for which the name Roseibium algae sp. nov. is proposed. The type strain is H3510^T (=KCTC 8206^T=MCCC 1K04325^T). The heterologously expressed inositol 2-dehydrogenase gene from strain H3510^T displayed high oxidation activity on myo-inositol and showed potential in the production of rare stereoisomers of inositol, such as scyllo-inositol.