A Gram-negative, rod-shaped aerobic bacterium designated as strain 2R12T was isolated from the rhizosphere soil of Hosta plantaginea. Phylogenetic analyses based on the 16S rRNA gene revealed that strain 2R12T should be assigned to the genus Chitinophaga with the highest sequence similarity to Chitinophaga arvensicola DSM 3695T (99.1 %) and Chitinophaga ginsengisegetis DSM 18108T (98.6 %). The major fatty acids of strain 2R12T (>10 %) were iso-C15 : 0, C16 :1 ω5c and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and five unidentified lipids. The predominant respiratory quinone was MK-7. The genomic DNA G+C content was 46.1 mol%. The average nucleotide identity values of strain 2R12T with C. arvensicola DSM 3695T and C. ginsengisegetis DSM 18108T were 77.9 and 78.8 %, respectively, while in silico DNA-DNA hybridization values for strain 2R12T with these strains were 22.8 and 23.3 %, respectively. Based on comparative analysis of phylogenetic, phylogenomic, phenotypic and chemotaxonomic characteristics, strain 2R12T represents a novel species in the genus Chitinophaga, for which the name Chitinophaga hostae sp. nov. is proposed. The type strain is 2R12T (=ACCC 61757T=JCM 34719T).
Keywords: Chitinophaga; Chitinophagaceae; Hosta plantaginea.