Robiginitalea biformata gen. nov., sp. nov., a novel marine bacterium in the family Flavobacteriaceae with a higher G+C content.

Two Gram-negative, chemoheterotrophic, non-motile, rust-coloured, marine strains were isolated from the western Sargasso Sea by high-throughput culturing. Characterization of the two strains by polyphasic approaches indicated that they are members of the same species. Phylogenetic analyses based on 16S rRNA gene sequences using three treeing algorithms revealed that the strains formed a coherent and novel genus-level lineage within the family Flavobacteriaceae. The dominant fatty acids were branched or hydroxy acids, i15 : 0, i15 : 1 and 3-OH i17 : 0 being the most abundant. The higher DNA G+C content of the strains (55-56 mol%) clearly differentiated them from other genera of the family Flavobacteriaceae (27-44 mol%). It is proposed, from the polyphasic evidence, that the strains be placed into a novel genus and a novel species named Robiginitalea biformata gen. nov., sp. nov., with strain HTCC2501T (=ATCC BAA-864T=KCTC 12146T) as the type strain.