Chitinolyticbacter albus sp. Nov., A Novel Chitin-Degrading Bacterium Isolated from Ancient Wood Rhizosphere Soil

In this study, a novel aerobic mesophilic bacterial strain with capable of degrading chitin, designated YIM B06366^T, was isolated and classified. The rod-shaped, Gram-stain-negative, on-spore-forming bacterium originated from rhizosphere soil sample collected in Kunming City, Yunnan Province, southwest PR China. Strain YIM B06366^T exhibited growth at temperatures between 20 and 35 °C (optimum, 30 °C) and at pH 6.0-8.0 (optimum, pH 6.0). The analysis of 16S rRNA gene sequence similarity revealed that strain YIM B06366^T was most closely related to type strain Chitinolyticbacter meiyuanensis SYBC-H1^T (98.9%). Phylogenetic analysis based on genome data indicated that strain YIM B06366^T should be assigned to the genus Chitinolyticbacter. The Average Nucleotide Identity (ANI) and digital DNA-DNA Hybridization (dDDH) values between strain YIM B06366^T and the reference strain Chitinolyticbacter meiyuanensis SYBC-H1^T were 84.4% and 27.7%, respectively. The major fatty acids included Summed Feature 3 (C_16:1 ω6c/C_16:1 ω7c), Summed Feature 8 (C_18:1 ω6c/C_18:1 ω7c), and C_16:0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, aminophospholipids, and two unidentified phospholipids. The predominant menaquinone was Q-8, and the genomic DNA G + C content was 64.1%. Considering the polyphasic taxonomic evidence, strain YIM B06366^T is proposed as a novel species within the genus Chitinolyticbacter, named Chitinolyticbacter albus sp. nov. (type strain YIM B06366^T = KCTC 92434^T = CCTCC AB 2022163^T).