Phylogenetic and taxonomic analysis of Neptunitalea chrysea gen. nov., sp. nov., a member of the phylum Bacteroidetes isolated from seawater by using an in situ cultivation technique

A novel pale-yellow coloured bacterial strain, designated AM327T, was isolated by using an in situ cultivation technique from seawater from the coastal zone around a shipyard located in Otsuchi Bay, Japan. The strain was found to be facultatively anaerobic, Gram-stain negative, chemoheterotrophic, non-motile and rod-shaped. Preliminary analysis based on the 16S rRNA gene sequence revealed that the novel isolate is affiliated with the family Flavobacteriaceae of the phylum Bacteroidetes and that it shows high sequence similarity (94.7 %) to Frondibacter aureus A5Q-67T. The strain can be differentiated phenotypically from recognised members of the family Flavobacteriaceae. The DNA G+C content of strain AM327T was determined to be 36.2 mol%; MK-6 was identified as the major menaquinone; iso-C15:0 and iso-C17:0 3-OH were identified as the major (>10 %) cellular fatty acids. The polar lipid profile was found to consist of phosphatidylethanolamine, an unidentified aminophospholipid, an unidentified glycolipid and two unidentified lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, strain AM327T is considered to represent a novel genus for which the name Neptunitalea chrysea gen. nov., sp. nov. is proposed. The type strain of N. chrysea is AM327T (=KCTC 32989T = NBRC 110019T).