Rubritalea sabuli sp. nov., a carotenoid- and squalene-producing member of the family Verrucomicrobiaceae, isolated from marine sediment.

The taxonomic status of a verrucomicrobial strain isolated from marine sediment was established based on a polyphasic examination. The novel isolate, strain YM29-052T, was obligately aerobic, Gram-negative, non-motile, coccoid or rod-shaped and chemoheterotrophic. Phylogenetic analyses based on 16S rRNA gene sequences demonstrated that the new isolate shared approximately 94-99 % sequence similarity with members of genus Rubritalea of the family Verrucomicrobiaceae within the phylum 'Verrucomicrobia'. Genomic DNA-DNA hybridization between strain YM29-052T and Rubritalea squalenifaciens HOact23T showed relatedness of <70 %, the value commonly accepted as the threshold for the phylogenetic definition of a species. Strain YM29-052T produces carotenoid compounds that render the cell biomass a pink colour; the strain also contains squalene. The cell-wall peptidoglycan of the novel strain contains muramic acid and meso-diaminopimelic acid. The DNA G+C content of strain YM29-052T was 47.7 mol%; MK-8 and MK-9 were the major menaquinones. The presence of iso-C14 : 0, iso-C16 : 0 and C16 : 1 omega 7c as major cellular fatty acids supported the identification of the novel isolate as a member of the genus Rubritalea. On the basis of polyphasic taxonomic evidence, it was concluded that strain YM29-052T should be classified within a novel species of the genus Rubritalea, for which the name Rubritalea sabuli sp. nov. is proposed. The type strain is YM29-052T (=MBIC08323T =KCTC 22127T).