Rhizobium albus sp. nov., Isolated from Lake Water in Xiamen, Fujian Province of China.

A Gram-stain-negative, aerobic bacterial strain, designated Y21T, was isolated from surface lake water in Xiamen, Fujian Province of China. Growth was observed at temperatures from 4 to 37 °C, at salinities from 0 to 7.0 % and at pH from 6.0 to 10.0. Optimum growth was observed at 28 °C, at pH 7.0 and with 1.5-2.0 % (w/v) NaCl. The highest similarity of 16S rRNA gene sequence between strain Y21T and the other strains was 96.9 %. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that the strain was a member of the genus Rhizobium, forming a distinct lineage with R. subbaraonis KCTC 23614T. The dominant fatty acids were summed feature 8 (comprising C18:1 ω7c and/or C18:1 ω6c), C18:1 ω7c 11-methyl, which accounted for 78.1 %. The G+C content of the chromosomal DNA was 60.9 mol%. The predominant respiratory quinone was ubiquinone-10. The polar lipids of strain Y21T were found to consist of five unidentified phospholipids and three unidentified aminolipids. According to its morphology, physiology, fatty acid composition and 16S rRNA sequence data, strain Y21T should be regarded as a new species of the genus Rhizobium, for which Rhizobium albus sp. nov. is proposed (type strain Y21T = MCCC 1F01210T = KCTC 42252T).