Thalassorhabdomicrobium marinisediminis gen. nov., sp. nov., a member of the family Hyphomonadaceae isolated from the Bohai Sea

A novel Gram-stain-negative bacterium, designated strain BH-SD16T, was isolated from a marine sediment sample collected in the Bohai Sea. Cells of strain BH-SD16T are aerobic, non-flagellated oval-shaped rods, showing oxidase- and catalase-positive activities. Growth occurs between 15–45 °C (optimum, 30 °C), at pH 6.0–9.0 (pH 7.0–7.5) and with 1–10 % (w/v) NaCl (3.0 %). Strain BH-SD16T contains C18 : 1 ω7c (49.2 %), C16 : 0 (17.7 %) and C18 : 1 ω7c 11-methyl (16.6 %) as the predominant fatty acids and ubiquinone-10 as the major respiratory quinone. The major polar lipids comprise phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol and two glycolipids. The size of the draft genome is 3 442 538 bp, including 3213 protein-coding genes, 40 tRNA genes and three rRNA genes, and the DNA G+C content is 63.4 mol%. Strain BH-SD16T shows the highest 16S rRNA gene sequence similarity to Pseudooctadecabacter jejudonensis (95.7 %), strains of the genus Octadecabacter (95.4–95.6 %) and strains of the genus Loktanella (93.8–95.4 %). Phylogenetic trees based on 16S rRNA gene sequences show that strain BH-SD16T forms a distinct lineage within the family Hyphomonadaceae , which is also confirmed in the multigenic phylogenetic tree calculated by RAxML. Based on the results of phenotypic, chemotaxonomic and phylogenetic analysis, strain BH-SD16T is considered to represent a novel genus and species in the family Hyphomonadaceae , for which the name Thalassorhabdomicrobium marinisediminis gen. nov., sp. nov. is proposed. The type strain is BH-SD16T (=CCTCC AB 2017073T=KCTC 62201T).