Marinomonas hwangdonensis sp. nov., isolated from seawater.

A Gram-negative, motile, rod-shaped bacterial strain, designated HDW-15(T), was isolated from seawater of the Yellow Sea, Korea, and subjected to a polyphasic taxonomic study. Strain HDW-15(T) grew optimally at pH 7.0-8.0, at 25 °C and in the presence of 2 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain HDW-15(T) fell within the clade comprising Marinomonas species, joining the type strain of Marinomonas arctica, with which it exhibited highest 16S rRNA gene sequence similarity (97.7 %). The 16S rRNA gene sequence similarity values between strain HDW-15(T) and the type strains of other Marinomonas species were in the range 93.7-97.2 %. Mean DNA-DNA relatedness values between strain HDW-15(T) and the type strains of M. arctica, Marinomonas polaris and Marinomonas pontica were 5.0-9.9 %. The DNA G+C content of the isolate was 48.7 mol%. Strain HDW-15(T) contained Q-8 as the predominant ubiquinone and C(18 : 1)ω7c, summed feature 3 (C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH) and C(16 : 0) as the major fatty acids. The major polar lipids found in strain HDW-15(T) were phosphatidylglycerol and phosphatidylethanolamine. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, showed that strain HDW-15(T) can be differentiated from other Marinomonas species. On the basis of the data presented, strain HDW-15(T) is considered to represent a novel species of the genus Marinomonas, for which the name Marinomonas hwangdonensis sp. nov. is proposed. The type strain is HDW-15(T) (= KCTC 23661(T) = CCUG 61321(T)).