Chitinophaga polysaccharea sp nov., an exopolysaccharide-producing bacterium isolated from the rhizoplane of Dioscorea japonica

A novel strain designated MRP-15(T), belonging to the class Sphingobacteriia (phylum Bacteroidetes), was isolated from the rhizoplane of Dioscorea japonica in South Korea and was characterized taxonomically using a polyphasic approach. The strain was found to comprise Gram-stain-negative, aerobic, non-motile, non-spore-forming rods. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain belonged to the genus Chitinophaga but was clearly separated from established species of the genus Chitinophaga. 16S rRNA gene sequence similarities between strain MRP-15(T) and type strains of established species of the genus Chitinophaga ranged from 90.3 to 97.8%. Phenotypic and chemotaxonomic data (major menaquinone, MK-7; major fatty acids, iso-C-15:0 and C-16:1 omega 5c) supported the affiliation of strain MRP-15T with the genus Chitinophaga. Therefore strain MRP-15(T) represents a novel species of the genus Chitinophaga, for which the name Chitinophaga polysaccharea sp. nov. is proposed. The type strain is MRP-15(T) (=KACC 17184(T)=NCAIMB 02530(T)).