Chitiniphilus purpureus sp. nov., a novel chitin-degrading bacterium isolated from crawfish pond sediment

Abstract

A novel Gram-stain-negative, curved rod-shaped, motile and chitin-degrading strain, designated CD1T, was isolated from crawfish pond sediment in Caidian District (30° 58′ N 114° 03′ E), Wuhan City, Hubei Province, PR China. Growth of this strain was observed at 15–40°C (optimum between 28 and 30 °C), at pH 7.0–9.0 (optimum between pH 7.0 and 8.0) and with 0–1 % (w/v) NaCl (optimum at 0 %). With respect to the 16S rRNA gene sequences, strain CD1T had the highest similarity (96.91–97.25 %) to four type strains of the genera ‘Chitinolyticbacter’ and Chitiniphilus within the family Chitinibacteraceae. The phylogenetic trees based on genome sequences and 16S rRNA gene sequences indicated that strain CD1T was close to members of these two genera, in particular to the genus Chitiniphilus. The genomic DNA G+C content of strain CD1T was 64.8 mol%. The average nucleotide identity and the Genome-to-Genome Distance Calculator results showed low relatedness (below 95 and 70 %, respectively) between strain CD1T and the closely related type strains. Ubiquinone-8 was the predominant quinone. The major cellular fatty acids were C10 : 0, C16 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c). The polar lipid profile was composed of a mixture of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unidentified lipids, two unidentified phospholipids, two unidentified aminolipids and an unidentified aminoglycolipid. On the basis of the evidences presented in this study, strain CD1T represents a novel species of the genus Chitiniphilus, for which the name Chitiniphilus purpureus sp. nov. is proposed, with strain CD1T (=CCTCC AB 2022395T=KCTC 92850T) as the type strain.