Marinobacter orientalis sp. nov., a thiosulfate-oxidizing bacterium isolated from a marine solar saltern.

A facultatively anaerobic bacterium, strain W62T, was isolated from the marine solar saltern in Weihai, China. Cells of the novel strain were Gram-stain negative, non-flagellated, non-gliding, rod-shaped and around 0.3-0.5 × 2.5-3.9 µm in size. Optimum growth occurred at 33-37 °C, with 3-5% (w/v) NaCl and at pH 7.0-7.5. On the basis of phylogenetic analysis of the 16S rRNA gene sequence, strain W62T had close relationship with Marinobacter vulgaris F01T (98.6%), Marinobacter confluentis KCTC 42705T (98.4%) and Marinobacter halotolerans NBRC 110910T (97.7%). Genome sequencing revealed a genome size of 4,050,555 bp, a G+C content of 57.3% and a complete sox system related to thiosulfate oxidization. Strain W62T had ubiquinone-9 as the sole respiratory quinone and possessed Summed Features 3 (C16:1 ω7c/C16:1 ω6c), C16:0 and C18:1 ω9c as the major fatty acids. The major polar lipids of strain W62T were identified as aminophospholipid, phosphatidylglycerol and phosphatidylethanolamine. According to the results of the phenotypic, chemotaxonomic characterization, phylogenetic properties and genome analysis, strain W62T should represent a novel specie of the genus Marinobacter, for which the name Marinobacter orientalis sp. nov. is proposed. The type strain is W62T (= MCCC 1H00317T = KCTC 62593T).