Reclassification of Flexibacter tractuosus NBRC 15981T as Marivirga harenae sp nov in the family Flammeovirgaceae

Flexibacter tractuosa [Lewin, 1969] was reclassified as Marivirga tractuosa. Flexibacter tractuosus NBRC 15981(T) was reclassified herein by using a polyphasic taxonomic approach. Cells of the strain were strictly aerobic, Gram-stain-negative, slender rods, which were motile by gliding. The major respiratory quinone was menaquinone-7 and the predominant (> 5 %) cellular fatty acids were iso-C-15 : 0, iso-G-C-15 : 1, C-16 : 1 omega 7c and iso-C-17 : 0 3-OH. The polar lipid pattern indicated the presence of a phosphatidylethanolamine, several unidentified aminolipids, glycolipids and five unidentified polar lipids. The G+ C content of the genomic DNA was 35.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain NBRC 15981(T) clustered with members of the genus Marivirga in the family Flammeovirgaceae of the phylum Bacteroidetes. Levels of DNA-DNA relatedness were less than 16% between strain NBRC 15981(T) and the two closely related species, Marivirga sericea NBRC 15983(T) and Marivirga tractuosa NBRC 15989(T). Strain NBRC 15981(T) could be differentiated from these type strains in the genus Marivirga based on the polar lipid pattern and the activity of alpha-chymotrypsin, as well as by aglucosidase and beta-glucosidase activity. On the basis of these results, NBRC 15981(T) is proposed as representing a novel species of the genus Marivirga, named Marivirga harenae sp. nov. The type strain is JK11(T) (= NBRC 15981(T) = NCIMB 1429(T)).