Chitinibacter mangrovi sp. nov., a Novel Chitin-Degrading Bacterium Isolated from Mangrove Sediment.

Abstract

A bacterial strain with chitin-degrading ability, designated FCG-7^T, was isolated from a mangrove sediment in Guangxi, PR China, and characterized using a polyphasic taxonomy approach. Cells of strain FCG-7^T were Gram-stain-negative, aerobic, rod-shaped and formed milky-white colonies. Growth occurred at 15-37 °C (optimum, 30 °C), at pH 7-9 (optimum, pH 7-8) and with 0-1% NaCl (optimum, 0.5%). The major isoprenoid quinone was ubiquinone-8 (Q-8). The predominant fatty acids were summed feature 3 (C_16:1 ω6c and/or C_16:1ω7c) and C_16:0. The polar lipids comprised phosphatidylethanolamine, diphosphatidylglycerol, five unidentified phospholipids and two unidentified aminophospholipids. The G + C content of the genomic DNA was 53.8%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain FCG-7^T belonged to the genus Chitinibacter and was closely related to Chitinibacter bivalviorum 2T18^T (similarity 99.29%) and Chitinibacter fontanus STM-7^T (similarity 98.85%). The average nucleotide identity (ANI) values of FCG-7^T and the above two type strains were 81.4-83.1%, and the digital DNA-DNA hybridization (dDDH) values were 22.9-24.3%. Based on the phylogenetic, phenotypic, chemotaxonomic and genotypic characteristics, strain FCG-7^T represents a novel species of the genus Chitinibacter, for which the name Chitinibacter mangrovi sp. nov. is proposed. The type strain is FCG-7^T (= KCTC 8742^T = GDMCC 1.4868^T).