Thalassotalea algicola sp. nov., an alginate-utilizing bacterium isolated from a red alga.

A facultatively anaerobic bacterium, strain M1531, was isolated from a red alga (Porphyra) at coastal water in Weihai, China. Cells of the novel strain were Gram-stain-negative, rod-shaped, motile by means of a single polar flagellum and around 0.6-0.8 × 2.0-3.0 µm in size. Optimum growth occurred at 30 °C, with 2% (w/v) NaCl and at pH 6.5-7.0. On the basis of the result of phylogenetic analysis of the 16S rRNA gene sequence, stain M1531 had close relative with Thalassotalea euphylliae KCTC 42743 (96.9%). Genome sequencing revealed a genome size of 4,061,950 bp, a G + C content of 39.1 mol% and four protein-coding genes related to the degradation of alginate. According to the data obtained, strain M1531 shared ANI value below 95-96%, dDDH value below 23.8% with the closely related type species. Strain M1531 had Q-8 as the predominant isoprenoid quinone and possessed Summed Features 3 (C ω7c/C ω6c), C and Summed Features 8 (C ω7c/C ω6c) as the major fatty acids. The polar lipids of strain M1531 were identified as phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid and four unidentified lipids. According to the results of the phenotypic, chemotaxonomic characterization, phylogenetic properties and genome analysis, strain M1531 represents a novel specie of the genus Thalassotalea, for which the name Thalassotalea algicola sp. nov. is proposed. The type strain is M1531 (= MCCC 1H00400 = KCTC 72865).