Thalassobius aquimarinus sp. nov., isolated from the Sea of Japan seashore.

An aerobic, Gram-negative, non-pigmented non-motile bacterium designed КMM 8518 was isolated from a seawater sampled from the Sea of Japan seashore. Strain КMM 8518 grew at 7-42 °C and in the presence of 1-7% NaCl. The phylogenetic analyses based on 16S rRNA gene and whole-genome sequences placed the novel strain КMM 8518 into the genus Thalassobius as a separate lineage. Strain КMM 8518 shared the highest 16S rRNA gene sequence similarity of 98% to Thalassobius gelatinovorus KCTC 22092 and similarity values of ≤ 97% to other recognized Thalassobius species. The average nucleotide identity and digital DNA-DNA hybridization values between strain КMM 8518 and T. gelatinovorus KCTC 22092 were 79.6% and 23.5%, respectively. The major respiratory quinone was ubiquinone-10. The major fatty acid was Cω7c followed by 11-methyl Cω7c. Polar lipids comprised phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminolipid, an unidentified phospholipid, and three unidentified lipids. The DNA G+C content of 62.7% was calculated from genome sequence analysis. Based on the phylogenetic analyses and distinctive phenotypic characteristics, the marine bacterium КMM 8518 is concluded to represent a novel species of the genus Thalassobius for which the name Thalassobius aquimarinus sp. nov. is proposed. The type strain of the species is strain KMM 8518 (= KCTC 82576).