Rubritalea halochordaticola sp. nov., a carotenoid-producing verrucomicrobial species isolated from a marine chordate
A Gram-negative-staining, obligately aerobic, non-motile, rod-shaped and chemoheterotrophic bacterium, designated strain MN1-1006T, was isolated from an ascidian (sea squirt) sample, and was studied using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the new isolate shared approximately 93–99% sequence similarity with recognized species of the genus Rubritalea within the phylum ‘Verrucomicrobia’. DNA–DNA hybridization values between strain MN1-1006T and Rubritalea squalenifaciens HOact23T and Rubritalea sabuli YM29-052T were 57% and 14.5%, respectively. Strain MN1-1006T produced carotenoid compounds that rendered the cell biomass a reddish pink colour. The strain also contained squalene. The cell-wall peptidoglycan of the novel strain contained muramic acid and meso-diaminopimelic acid. The DNA G+C content of strain MN1-1006T was 51.4 mol%. The major cellular fatty acids were iso-C14:0, iso-C16:0 and anteiso-C15:0. The major isoprenoid quinone was MK-9. On the basis of these data, it was concluded that strain MN1-1006T represents a novel species of the genus Rubritalea, for which the name Rubritalea halochordaticola sp. nov. is proposed. The type strain is MN1-1006T ( = KCTC 23186T = NBRC 107102T).