Pseudomonas insulae sp. nov., isolated from island soil

Abstract

A novel Gram-stain-negative, rod-shaped, aerobic and motile bacterium designated strain UL073^T was isolated from a forest soil of an island, and subjected to taxonomic characterization. Strain UL073^T grew at 10-37 °C (optimum, 30 °C), at pH 5.0-10.0 (optimum, pH 7.0) and in the presence of 0-3 % NaCl (optimum, 0 %), respectively. Strain UL073^T showed the highest sequence similarity to Pseudomonas lalkuanensis PE08^T based on 16S rRNA gene analysis with a sequence similarity of 98.08 %, which was well below the suggested cutoff for species distinction. The 16S rRNA gene tree as well as the multilocus sequence analysis and genome-based trees indicated the independent taxonomic position of strain UL073^T, and the orthologous average nucleotide identity and in silico DNA-DNA hybridization values between strain UL073^T and related species were no higher than 84.7 and 28.3% respectively, thus confirming the distinctive taxonomic position of the strain. The chemotaxonomic properties were consistent with those of the genus, as the major fatty acids of the strain were a summed feature consisting of C_{18 : 1} ω7c/C_{18 : 1} ω6c (31.4 %), another summed feature consisting of C_{16 : 1} ω7c/C_{16 : 1} ω6c (23.1 %), and C_{16 : 0} (22.0 %), the major respiratory quinone was ubiquinone 9, and the major polar lipids were phosphatidylethanolamine and diphosphatidylglycerol. The genome size and DNA G+C content of strain UL073^T were 4.87 Mbp and 65.9 mol%. On the basis of phenotypic and phylogenetic evidence, strain UL073^T should be classified as representing a novel species of Pseudomonas, for which the name Pseudomonas insulae sp. nov. (type strain=UL073^T=KCTC 82407^T=JCM 34511^T) is proposed.

Keywords: Pseudomonas insulae sp. nov.; island soil; plant growth promoting potential.