Cellvibrio chitinivorans sp. nov., a chitinolytic bacterium isolated from an intertidal mudflat

A novel chitinolytic bacterium, designated as NN19^T, was isolated from the intertidal mudflat in Leizhou, Guangdong Province, PR China, and subjected to polyphasic taxonomy studies. Strain NN19^T is a Gram-negative short rod-shaped bacterium that is motile via a single polar flagellum. Growth occurred at temperatures of 15 °C and 37 °C (optimal 30 °C), pH 6.5-8.0 (optimal pH 7.0) and sodium chloride concentration of 0%-3% (optimal 0.5%-1%). It was identified as a Cellvibrio species based on the results of 16S rRNA gene sequence analysis, and it showed the highest degree of sequence similarity with Cellvibrio fontiphilus MVW-40^T (97.87%). The main fatty acids of NN19^T were found to be summed feature 3 (C_16 : 1  ω7c/C_16 : 1  ω6c), C_16 : 0 and C_18 : 1  ω7c. The polar lipid profile included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phospholipid. The respiratory quinone was shown to be ubiquinone-8. Strain NN19^T had a genome of 4.46 Mb with a G+C content of 47.82%. The average nucleotide identity and digital DNA-DNA hybridization value between strain NN19^T and C. fontiphilus MVW-40^T are 75.47% and 20.4%, respectively. Based on phylogenetic analysis and phenotypic data, we concluded that strain NN19^T represents a novel species belonging to the genus Cellvibrio, for which the name Cellvibrio chitinivorans sp. nov. is proposed. The type strain is NN19^T (=MCCC 1K08847^T=KCTC 8393^T).