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

Abstract

A Gram-stain-negative, facultatively anaerobic, non-motile, rod-shaped bacterial strain, designated HL-MP18T, 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-MP18Twas affiliated to the genusRoseovariuswith close relativesRoseovarius carneusLXJ103T(96.8 %) andRoseovarius litorisediminisKCTC 32327T(96.5 %). The complete genome sequence of strain HL-MP18Tcomprised 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-MP18Twas consistently discriminated from its closely related taxa in the genusRoseovarius. Strain HL-MP18Tshowed optimal growth at 25 °C, pH 7.0 and 2.5 % (w/v) sea salts. The major cellular fatty acids were C18 : 1 ω6cand/or C18 : 1 ω7c(49.6 %), C19 : 0cycloω8c(13.5 %), and C16 : 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-MP18Tis distinguishable from the recognized species of the genusRoseovarius. Therefore, we propose that strain HL-MP18Trepresents a novel species belonging to the genusRoseovarius, for which the nameRoseovarius pelagicussp. nov. is proposed. The type strain is HL-MP18T(=KCCM 90405T=JCM 35639T).