Maribacter confluentis sp. nov., isolated from the junction between the ocean and a freshwater spring

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated, non-gliding and rod-shaped bacterial strain, SSK2-2^T, was isolated from the place where the ocean and a freshwater spring meet at Jeju island, South Korea. Strain SSK2-2^T grew optimally at 30°C, at pH 7.0–8.0 and in the presence of 2.0–3.0% (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain SSK2-2^T fell within the clade comprising the type strains of species of the genus Maribacter, joining the type strain ofMaribacter sedimenticola with which it shared 99.4% similarity. Sequence similarities to the type strains of other Maribacter species were 94.6–98.2%. Strain SSK2-2^T contained MK-6 as the predominant menaquinone and iso-C_17:0 3-OH, iso-C_15:0, iso-C_15:1 G, summed feature 3 (C_16:1ω7c and/or C_16:1ω6c) and summed feature 9 (iso-C_17:1ω9c and/or 10-methyl C_16:0) as the major fatty acids. The major polar lipids of strain SSK2-2^T were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain SSK2-2^Twas 38.2mol% and mean levels of DNA–DNA relatedness with the type strains of four phylogenetically related species of the genus Maribacter were 11–24%. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain SSK2-2^T is separate from other Maribacter species. On the basis of the data presented, strain SSK2-2^T is considered to represent a novel species of the genus Maribacter, for which the name Maribacter confluentis sp. nov. is proposed. The type strain is SSK2-2^T (=KCTC 42604^T=CECT 8869^T).