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 <i>Cellvibrio</i> species based on the results of 16S rRNA gene sequence analysis, and it showed the highest degree of sequence similarity with <i>Cellvibrio fontiphilus</i> MVW-40^T (97.87%). The main fatty acids of NN19^T were found to be summed feature 3 (C_{16 : 1} <i> ω</i>7<i>c</i>/C_{16 : 1} <i> ω</i>6<i>c</i>), C_{16 : 0} and C_{18 : 1} <i> ω</i>7<i>c</i>. 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 <i>C. fontiphilus</i> 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 <i>Cellvibrio</i>, for which the name <i>Cellvibrio chitinivorans</i> sp. nov. is proposed. The type strain is NN19^T (=MCCC 1K08847^T=KCTC 8393^T).