Pedobacter Chitinilyticus Sp. Nov., A Chitin-Degrading Bacterium Isolated From Wheat Leaf Tissue

A bacterium, designated strain CM134L-2(T), was isolated from a chitin-enriched wheat leaf microbiome in Chengdu, Sichuan province, China. It was Gram-stain-negative, strictly aerobic, non-spore-forming, motile, rod-shaped, and bright yellow in colour. Strain CM134L-2(T) grew at 4-35 degrees C, at pH 6.0-9.0 and could use chitin as the only carbon resource. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain CM134L-2(T) was most closely related to Pedobacter nanyangensis Q-4(T) (97.7 %) and Pedobacter zeaxanthinifaciens TDMA-5(T) (97.4 %). Digital DNA-DNA hybridization (dDDH) values between strain CM134L-2(T) with these two type strains were 26.8 and 20.8 %, respectively, and average nucleotide identity (ANI) values were 83.2 and 76.2 %; these values are lower than the proposed and generally accepted species boundaries of 70 % for dDDH and 95-96 % for ANI, which suggests strain CM134L-2(T) represents a novel species. The genomic DNA G+C content of strain CM134L-2(T) was 39.3 mol%, menaquinone-7 was the major respiratory quinone, phosphatidylethanolamine was the major polar lipid and the major components of the cellular fatty acids were iso-C-15:0, and C-16 :1 omega 7c/C-16:1 omega 6C (summed feature 3); these features supported the affiliation of strain CM134L-2(T) to the genus Pedobacter. Overall, strain CM134L-2(T) belongs to the genus Pedobacter, but can be classified as a novel species, for which the name Pedobacter chitinilyticus sp. nov. is proposed. The type strain is CM134L-2(T) (=CGMCC 1.16520(T)=KCTC 62643(T)).