Chitinophaga extrema sp. nov., isolated from subsurface soil and leaf litter in a tropical peat swamp forest

A Gram-negative, filamentous aerobic bacterium designated as strain Mgbs1^T was isolated on 12 April 2017 from the subsurface soil and leaf litter substrate at the base of a Koompassia malaccensis tree in a tropical peat swamp forest in the northern regions of the state of Selangor, Malaysia (3° 39' 04.7' N 101° 17' 43.7'' E). Phylogenetic analyses based on the full 16S rRNA sequence revealed that strain Mgbs1^T belongs to the genus Chitinophaga with the greatest sequence similarity to Chitinophaga terrae KP01^T (97.65 %), Chitinophaga jiangningensis DSM27406^T (97.58 %), and Chitinophaga dinghuensis DHOC24^T (97.17 %). The major fatty acids of strain Mgbs1^T (>10 %) are iso-C_15 : 0, C_16 : 1  ω5c and iso-C_17 : 0 3-OH while the predominant respiratory quinone is menaquinone-7. Strain Mgbs1^T has a complete genome size of 8.03 Mb, with a G+C content of 48.5 mol%. The DNA-DNA hybridization (DDH) score between strain Mgbs1^T and C. jiangningensis DSM27406^T was 15.9 %, while in silico DDH values of strain Mgbs1^T against C. dinghuensis DHOC24^T and C. terrae KP01^T were 20.0 and 19.10% respectively. Concurrently, Average Nucleotide Identity (ANI) scores between strain Mgbs1^T against all three reference strains are 73.2 %. Based on the phenotypic, chemotaxonomic, and phylogenetic consensus, strain Mgbs1^T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga extrema sp. nov. is proposed (=DSM 108835^T=JCM 33276^T).