Chitiniphilus eburneus sp. nov., a novel chitinolytic bacterium isolated from sludge

A novel Gram-stain-negative, curved rod-shaped, motile and non-endospore-forming strain, designated HX-2-15^T, was isolated from activated sludge of agricultural chemical plant in Nanjing, Jiangsu province, PR China (32° 03' N, 118° 46' E) . Growth was observed at 15-37 °C (optimum between 25 and 30 °C), at pH 6.0-8.0 (optimum at pH 7.0) and with 0-3.0 % (w/v) NaCl (optimum at 0.5 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain showed closest affiliation to Chitiniphilus shinanonensis SAY3^T, with a sequence similarity of 99.0 %. The predominant cellular fatty acids were C_16:0, C_17:0 cyclo and summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c). The major quinone was ubiquinone Q-8 . The polar lipid profile was composed of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, three unidentified phospholipids, one unidentified lipid and one unidentified aminophosphoglycolipid . The genomic DNA G+C content of the strain was 63.6 mol%. The ANI and dDDH values obtained between the genomes of HX-2-15^T and C. shinanonensis SAY3^T were 85.3 and 29.3 % respectively. On the basis of data from phenotypic, chemotaxonomic and genotypic analysis, strain HX-2-15^T represents a novel species of the genus Chitiniphilus, for which the name Chitiniphilus eburneus sp. nov. is proposed. The type strain is HX-2-15^T (=KCTC 72286^T=CCTCC AB 2019178^T).