Celeribacter ethanolicus sp. nov., isolated from seawater of the South China Sea

Abstract:

[Objective] A novel Celeribacter strain NH195^T was isolated from seawater of the South China Sea and was subjected to polyphasic taxonomic study. [Methods] Phenotypic, genotypic and chemotaxonomic characterizations, as well as phylogenetic inference were performed in this study. [Results] Strain NH195^T was a Gram-stain-negative, aerobic, rod-shaped, non-motile bacterium that accumulates poly-β-hydroxybutyrate (PHB). The isolate grew in media containing 0.5%-10.0% (W/V) NaCl (optimally at 1.0%-3.0%) at 20-40 ℃ and pH 5.0-9.0, and was positive for oxidase, catalase and urease. The respiratory quinone was Q-10. The major fatty acids (>10%) were C_18:1ω7c, C_18:1ω6c and 11 methyl C_18:1ω7c. The major polar lipids were phosphatidylcholine (PC), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), one unidentified aminolipid and two unidentified lipids. The genomic DNA G+C content was 61.3 mol%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain NH195^T could be assigned to the genus Celeribacter. The 16S rRNA gene sequence similarities between the isolate and the type strains of Celeribacter species with validly published names were in the range 94.4%-97.7%. Strain NH195^T exhibited average nucleotide identity (ANI) values of 78.6% and 78.0% to C. halophilus ZXM137^T and C. indicus P73^T respectively. The genome-to-genome distance analysis revealed that strain NH195^T shared 26.1% DNA relatedness with C. halophilus ZXM137^T and 23.0% with C. indicus P73^T, respectively. [Conclusion] On the basis of phenotypic and genotypic characteristics, strain NH195^T represents a novel species within the genus Celeribacter, for which the name Celeribacter ethanolicus is proposed. The type strain is NH195^T (=CGMCC 1.15406^T=JCM 31095^T).

Key words:Celeribacter ethanolicus|Polyphasic taxonomy|Seawater|South China Sea