Marinobacterium aestuariivivens sp. nov., isolated from a tidal flat.

A Gram-stain-negative, motile, aerobic, rod- or ovoid-shaped bacterium, designated DB-1T, was isolated from a tidal flat on the Yellow Sea in South Korea and subjected to a taxonomic study using a polyphasic approach. Strain DB-1T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 0.5-2.0% (w/v) NaCl. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain DB-1T falls within the clade comprising species of the genus Marinobacterium, clustering coherently with the type strain of Marinobacterium nitratireducens and showing a sequence similarity value of 98.4 %. The novel strain exhibited 16S rRNA gene sequence similarities of 91.5-94.4 % to the type strains of other species of the genus Marinobacterium. Strain DB-1T contained Q-8 as the predominant ubiquinone and C18:1ω7c, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and C16:0 as the major fatty acids. The major polar lipids detected in strain DB-1T were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid, one unidentified glycolipid, one unidentified phospholipid and two unidentified lipids. The DNA G+C content of strain DB-1T was 62.3 mol% and the mean DNA-DNA relatedness value with the type strain of M. nitratireducens was 21±4.6%. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain DB-1T is separated from recognized species of the genus Marinobacterium. On the basis of the data presented, strain DB-1T is considered to represent a novel species of the genus Marinobacterium, for which the name Marinobacterium aestuariivivens sp. nov. is proposed. The type strain is DB-1T (=KCTC 42778T=NBRC 111756T).