Pseudomonas urumqiensis sp. nov., isolated from rhizosphere soil of Alhagi sparsifolia

Abstract

A motile, Gram-stain-negative, fusiform-shaped bacterium, designated strain T3^T, was isolated from rhizosphere soil of Alhagi sparsifolia, collected from Xinjiang, PR China. Strain T3^T grew at 15-42 °C, pH 4-9 and 1-6 % (w/v) NaCl concentrations. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain T3^T belonged to the genus Pseudomonas and showed highest similarity of 98.6 % to Pseudomonas azotifigens JCM 12708^T, followed by Pseudomonas balearica DSM 6083^T (97.8 %), Pseudomonas matsuisoli JCM 30078^T (97.7 %), Pseudomonas furukawaii KF707^T (97.7 %), Pseudomonas tarimensis CCTCC AB 2013065^T (97.3 %) and Pseudomonas indica DSM 14015^T (97.1 %). Analysis based on concatenated gene sequences of 16S rRNA, rpoB and gyrB further confirmed the phylogenetic assignment of strain T3^T. The Genome-to-Genome Distance Calculator results for P. azotifigens JCM12708^T and P. balearica DSM 6083^T were 28.7±4.4% and 24.1±2.4 %, and the average nucleotide identity scores were 81.3 and 78.1 %. The major polar lipids of strain T3^T were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The predominant quinone was Q-9. The major fatty acids comprised summed feature 8 (C18 : 1ω6c/C18 : 1ω7c; 37.7 %), summed feature 3 (C16 : 1ω6c/C16 : 1ω7c; 28.2 %), C16 : 0 (15.6 %), C12 : 0 (7.8 %), C10 : 03-OH (3.0 %) and C12 : 03-OH (2.6 %). The G+C content of the genomic DNA of the type strain was 65.3 mol%. It is obvious from the phylogenetic, phenotypic and chemotaxonomic data that strain T3^T represents a novel species of the genus Pseudomonas, for which the name Pseudomonasurumqiensis sp. nov., is proposed. The type strain is T3^T (=ACCC 60124^T=JCM 32830^T).

Keywords: Alhagi sparsifolia; Pseudomonas urumqiensis; bacterium; rhizosphere soil.