Marinobacter liaoningensis sp. nov., isolated from the marine sediment

A Gram-stain-negative, facultatively anaerobic, rod-shaped bacterial strain, namely F4206^T, was isolated from the sediments of Beihai Red Beach, China. The optimal temperature, pH, and NaCl concentration of F4206^T were 20-40 °C, pH 6.5, and 10%. The digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI) and average amino acid identity (AAI) values between strain F4206^T and its closest relatives ranged from 20.5 to 44.3%, 78.2 to 80.5% and 65.0 to 94.8% respectively, which are well below the established species delineation thresholds of 70%, 95% and 95%. This conclusive genomic evidence for novelty is further supported by phylogenetic analysis, which placed strain F4206^T within a distinct lineage closely related to Marinobacter qingdaonensis ASW11-75 ^T and Marinobacter arenosus CAU 1620 ^T, with a 16S rRNA gene sequence similarity of 98.22%. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain F4206^T formed a distinct lineage within the genus Marinobacter. The digital DNA-DNA hybridization and average nucleotide identity values between strain F4206^T and closely related strains were 20.5-44.3% and 78.2-80.5%, much lower than the cutoff values of 70% and 95%, respectively. The dominant respiratory quinone of the strain was ubiquinone-9. The main fatty acids (> 5%) were C_16:0, C_18:1 ω9c, C_16:1 ω9c, summed feature 3, C_12:0 3-OH and C_12:0. The major polar lipids of strain F4206^T were phosphatidylethanolamine, phosphatidylglycerol, aminolipid, and aminophospholipid. The DNA G + C content of F4206^T was 58.5%. According to phenotypic, phylogenetic, and chemotaxonomic analysis, strain F4206^T was considered as a new species of Marinobacter, with the name of Marinobacter liaoningensis sp. nov. F4206^T. The type strain is F4206^T (= CGMCC 1.19487 ^T = KCTC 92054 ^T).