A Gram-stain negative, aerobic, non-motile, short-rod-shaped bacterium, designated KBL-4-9 T , was isolated from the storage liquid in the stems of Populus euphratica trees in Xinjiang, PR China. Strain KBL-4-9 T grew at 4-45 8C (optimum 37 8C), 1-3 % (w/v) NaCl (optimum 1 %, w/v) and pH 5.5-9.5 (optimum pH 7.5). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain KBL-4-9 T belonged to the genus Pseudomonas and showed the highest 16S rRNA gene sequence similarity of 97.36 % to Pseudomonas pelagia CL-AP6 T , followed by Pseudomonas xinjiangensis S3-3 T (97.16 %), Pseudomonas sabulinigri J64 T (97.15 %) and Pseudomonas xiamenensis C10-2 T (96.47 %). Analysis of strain KBL-4-9 T based on the three housekeeping genes, rpoB, rpoD and gyrB, further confirmed the phylogenetic assignment of the isolates. The DNA G+C content was 61.6 mol% (SD52.19). DNA-DNA hybridization with P. pelagia CL-AP6 T , P. xinjiangensis S3-3 T and P. sabulinigri J64 T revealed 49.3 % (SD53.04), 41.2 % and 52.5 % (SD54.45) relatedness, respectively. The major cellular fatty acids of strain KBL-4-9 T were C 16 : 0 , C 12 : 0 , summed feature 8 (C 18 : 1 v7c and/or C 18 : 1 v6c) and C 17 : 0 cyclo. The major isoprenoid quinone was Q-9. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidylcholine. On the basis of phenotypic, chemotaxonomic and phylogenetic properties, strain KBL-4-9 T is considered to represents a novel species of the genus Pseudomonas, for which the name Pseudomonas populi sp. nov. is proposed. The type strain is

An endophytic bacterium, designated K-38 T , was isolated from the storage liquid in the stems of Populus euphratica trees at the ancient Ugan River in Xinjiang, PR China. Strain K-38 T was found to be rod-shaped, Gram-stain-negative, aerobic, non-motile and non-spore-forming. Strain K-38 T grew at temperatures of 25-37 6C (optimum, 28 6C), at pH 6.0-9.0 (optimum, pH 7.5) and in the presence of 0-3 % (w/v) NaCl with 1 % as the optimum concentration for growth. According to phylogenetic analysis based on 16S rRNA gene sequences, strain K-38 T was assigned to the genus Rhizobium with highest 16S rRNA gene sequence similarity of 97.2 % to Rhizobium rosettiformans W3 T , followed by Rhizobium nepotum 39/7 T (96.5 %) and Rhizobium borbori DN316 T (96.2 %). Phylogenetic analysis of strain K-38 T based on the protein coding genes recA, atpD and nifH confirmed (similarities were less than 90 %) it to be a representative of a distinctly delineated species of the genus Rhizobium. The DNA G+C content was determined to be 63.5 mol%. DNA-DNA relatedness between K-38 T and R. rosettiformans W3 T was 48.4 %, indicating genetic separation of strain K-38 T from the latter strain. The major components of the cellular fatty acids in strain K-38 T were revealed to be summed feature 8 (comprising C 18 : 1 v7c and/or C 18 : 1 v6c; 57.2 %), C 16 : 0 (13.6 %) and summed feature 2 (comprising C 12 : 0 aldehyde, C 14 : 0 3-OH/iso-C 16 : 1 I and/or unknown ECL 10.928; 11.0 %). Polar lipids of strain K-38 T include phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, two unidentified aminophospholipids and two unidentified phospholipids. Q-10 was the major quinone in strain K-38 T . Based on phenotypic, chemotaxonomic and phylogenetic properties, strain K-38 T represents a novel species of the genus Rhizobium, for which the name Rhizobium populi sp. nov. is proposed. The type strain is