Tenacibaculum halocynthiae sp. nov., a member of the family Flavobacteriaceae isolated from sea squirt Halocynthia roretzi

A Gram-negative, non-spore-forming, aerobic, non-flagellated, non-gliding and rod-shaped bacterial strain, designated P-R2A1-2^T, was isolated from sea squirt (Halocynthia roretzi) collected from the South Sea, Korea. It grew optimally at 25–28 °C, at pH 7.0–8.0 and in the presence of 2 % (w/v) NaCl. Neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that the strain fell within the clade comprising Tenacibaculum species. Strain P-R2A1-2^T exhibited the highest 16S rRNA gene sequence similarity values of 97.6, 97.2 and 97.0 % to Tenacibaculum aestuarii SMK-4^T, T. lutimaris TF-26^T and T. aiptasiae a4^T, respectively, and of 94.5–96.8 % to the type strains of the other Tenacibaculum species. Strain P-R2A1-2^T contained MK-6 as the predominant menaquinone and C_16:1 ω7c and/or iso-C_15:0 2-OH, iso-C_15:0 3-OH and iso-C_15:0 as the major fatty acids. The DNA G + C content of strain P-R2A1-2^T was 30.7 mol % and its DNA–DNA relatedness values with the type strains of T. aestuarii, T. lutimaris and T. aiptasiae were 17 ± 4.2, 21 ± 6.1 and 16 ± 5.2 %, respectively. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that the novel strain is separate from other Tenacibaculum species. On the basis of the data presented, strain P-R2A1-2^T is considered to represent a novel species of the genus Tenacibaculum, for which the name Tenacibaculum halocynthiae sp. nov. is proposed. The type strain is P-R2A1-2^T (=KCTC 32262^T = CCUG 63681^T).