Thalassospira povalilytica sp. nov., a polyvinyl-alcohol-degrading marine bacterium

A polyvinyl-alcohol-degrading marine bacterium was isolated from plastic rope litter found in Tokyo Bay, Japan. The isolated strain, Zumi 95^T, was a Gram-reaction-negative, non-spore-forming and facultatively anaerobic chemo-organotroph. The major respiratory quinone was Q-10. The predominant fatty acids were C_18 : 1ω7c and C_16 : 0. On the basis of 16S rRNA gene sequence analysis, the isolated strain was closely affiliated with members of the genus Thalassospira in the class Alphaproteobacteria. The DNA G+C content of the novel strain was 55.1 mol%. The hybridization values for DNA–DNA relatedness between this strain and four reference strains representing species of the genus Thalassospira were significantly lower than that accepted as the phylogenetic definition of a species. On the basis of differences in taxonomic characteristics, the isolated strain represents a novel species of the genus Thalassospira for which the name Thalassospira povalilytica sp. nov. (type strain Zumi 95^T = JCM 18746^T = DSM 26719^T) is proposed.