Dokdonia ponticola sp. nov., A Carrageenan-Degrading Bacterium of the Family Flavobacteriaceae Isolated from Seawater.

A Gram-stain-negative, aerobic, non-motile, and carrageenan-degrading bacterial strain, designated OISW-17T, was isolated from seawater around Oido, an island of South Korea, and its taxonomic position was determined using a polyphasic study. Optimal growth of the novel strain occurred at 20-25 °C and in the presence of 2.0% (w/v) NaCl. Phylogenetic trees using 16S rRNA gene sequences showed that strain OISW-17T forms a cluster with the type strains of Dokdonia species. The novel strain exhibited 16S rRNA gene sequence similarities of 95.7-96.3% to the type strains of Dokdonia species and of < 93.4% to the type strains of the other recognized species. Menaquinone-6 (MK-6) was found as the predominant menaquinone and iso-C15:0, iso-C15:1 G, and iso-C17:0 3-OH were the major fatty acids. Phosphatidylethanolamine, one unidentified lipid, and one unidentified aminolipid were major polar lipids detected in strain OISW-17T. Strain OISW-17T had DNA G+C content of 39.7 mol%. The differential phenotypic characteristics, along with the phylogenetic data, made strain OISW-17T to be distinct from recognized species of the genus Dokdonia. On the basis of the data given, strain OISW-17T represents a novel species of the genus Dokdonia, for which the name Dokdonia ponticola sp. nov. is proposed. The type strain of the novel species is OISW-17T (= KACC 19437T = KCTC 62187T = CGMCC 1.16527T).