Pseudomonas tarimensis sp. nov., an endophytic bacteria isolated from Populus euphratica

Abstract

An endophytic bacterium, MA-69^T, was isolated from the storage liquid in the stems of Populuseuphratica trees at the ancient Ugan River in Xinjiang, PR China. Strain MA-69^T was found to be short rod-shaped, Gram-stain-negative, non-spore-forming, aerobic and motile by means of a monopolar flagellum. According to phylogenetic analysis based on 16S rRNA gene sequences, strain MA-69^T was assigned to the genus Pseudomonas with highest 16S rRNA gene sequence similarity of 97.5 % to Pseudomonas azotifigens JCM 12708^T, followed by Pseudomonas matsuisoli JCM 30078^T (97.5 %), Pseudomonas balearica DSM 6083^T (97.1 %), Azotobacter salinestris ATCC 49674^T (96.1 %) and Pseudomonas indica DSM 14015^T (95.9 %). Analysis of strain MA-69^T based on the three housekeeping genes, rpoB, rpoD and gyrB, further confirmed the isolate to be distinctly delineated from species of the genus Pseudomonas. The DNA G+C content of strain MA-69^T was 64.1 mol%. DNA-DNA hybridization with Pseudomonas azotifigens JCM 12708^T, Pseudomonas matsuisoli JCM 30078^T and Pseudomonas balearica DSM 6083^T revealed 62.9, 60.1 and 49.0 % relatedness, respectively. The major fatty acids in strain MA-69^T were summed feature 3 (25.7 %), summed feature 8 (24.0 %), C19 : 0cyclo ω8c (19.9 %), C16 : 0 (14.6 %) and C12 : 0 (6.3 %). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Q-9 was the major quinone in strain MA-69^T. Based on phenotypic, chemotaxonomic and phylogenetic properties, strain MA-69^T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas tarimensis sp. nov. is proposed. The type strain is MA-69^T (=CCTCC AB 2013065^T=KCTC 42447^T).

Keywords: Populus euphratica; Pseudomonas; endophytic bacteria.