Patiriisocius marinistellae gen. nov., sp. nov., isolated from the starfish Patiria pectinifera, and reclassification of Ulvibacter marinus as a member of the genus Patiriisocius comb. nov.

A marine strain, designated KK4 T , was isolated from the surface of a starfish, Patiria pectinifera , which was collected from seawater off the coast of Hokkaido, Japan. Strain KK4 T is a Gram-stain-negative, non-spore-forming, rod-shaped, aerobic bacterium that forms yellow-pigmented colonies. A phylogenetic relationship analysis, based on 16S rRNA gene sequences, revealed that strain KK4 T was closely related to Ulvibacter marinus IMCC12008 T , Ulvibacter antarcticus IMCC3101 T and Ulvibacter litoralis KMM 3912 T , with similarities of 96.9, 95.8 and 95.6 %, respectively, but low sequence similarities (<94 %) among other genera in the family Flavobacteriaceae . Genomic similarities between strain KK4 T and the three Ulvibacter type strains based on average nucleotide identity and digital DNA–DNA hybridization values were lower than the species delineation thresholds. Moreover, phylogenetic tree based on genome sequences showed that strain KK4 T was clustered with U. marinus IMCC12008 T and formed a branch independent from the cluster including type species of the genera Ulvibacter , Marixanthomonas , Marinirhabdus , Aureitalea and Aequorivita . Amino acid identity values between strain KK4 T / U. marinus IMCC12008 T and the neighbour type species/strains were 61.9–68.2% and 61.5–67.4 %, which were lower than the genus delineation threshold, implying the novel genus status of strain KK4 T . Strain KK4 T growth occurred at pH 6.0–9.0, 4–30 °C and in NaCl concentrations of 0.5–5.0 %, and optimally at pH 7.0, 25 °C and 3.0 %, respectively. Unlike Ulvibacter strains, strain KK4 T could assimilate glucose, mannose, galactose and acetate. The major quinone and fatty acids were menaquinone-6 and iso-C 15 : 0 (27.5 %), iso-C 15 : 1 G (22.5 %) and iso-C 17 : 0 3-OH (12.8 %), respectively. Based on genetic, phylogenetic and phenotypic properties, strain KK4 T represents a novel species of the genus Patiriisocius , for which the name Patiriisocius marinistellae gen. nov., sp. nov. is proposed. The type strain is KK4 T (=JCM 33344 T =KCTC 72225 T ). In addition, based on the current data, Ulvibacter marinus should be reclassified as Patiriisocius marinus comb. nov.