Roseovarius pelagicus sp. nov., a facultatively anaerobic bacterium with potential for degrading polypropylene, isolated from Arctic seawater

A Gram-stain-negative, facultatively anaerobic, non-motile, rod-shaped bacterial strain, designated HL-MP18 T , was isolated from Arctic seawater after a prolonged incubation employing polypropylene as the sole carbon source. Phylogenetic analyses of the 16S rRNA gene sequence revealed that strain HL-MP18 T was affiliated to the genus Roseovarius with close relatives Roseovarius carneus LXJ103 T (96.8 %) and Roseovarius litorisediminis KCTC 32327 T (96.5 %). The complete genome sequence of strain HL-MP18 T comprised a circular chromosome of 3.86 Mbp and two circular plasmids of 0.17 and 0.24 Mbp. Genomic comparisons based on average nucleotide identity and digital DNA–DNA hybridization showed that strain HL-MP18 T was consistently discriminated from its closely related taxa in the genus Roseovarius . Strain HL-MP18 T showed optimal growth at 25 °C, pH 7.0 and 2.5 % (w/v) sea salts. The major cellular fatty acids were C 18 : 1 ω 6 c and/or C 18 : 1 ω 7 c (49.6 %), C 19 : 0 cyclo ω 8 c (13.5 %), and C 16 : 0 (12.8 %). The major respiratory quinone was ubiquinone-10. The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid and three unidentified lipids. The genomic DNA G+C content of the strain was 59.2 mol%. The phylogenetic, genomic, phenotypic and chemotaxonomic results indicate that strain HL-MP18 T is distinguishable from the recognized species of the genus Roseovarius . Therefore, we propose that strain HL-MP18 T represents a novel species belonging to the genus Roseovarius , for which the name Roseovarius pelagicus sp. nov. is proposed. The type strain is HL-MP18 T (=KCCM 90405 T =JCM 35639 T ).