ABSTRACT
A Gram-stain negative, aerobic, non-motile, short-rod-shaped bacterium, designated KBL-4-9T, was isolated from the storage liquid in the stems of Populus euphratica trees in Xinjiang, PR China. Strain KBL-4-9T grew at 4-45 °C (optimum 37 °C), 1-3â% (w/v) NaCl (optimum 1â%, w/v) and pH 5.5-9.5 (optimum pH 7.5). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain KBL-4-9T belonged to the genus Pseudomonas and showed the highest 16S rRNA gene sequence similarity of 97.36â% to Pseudomonas pelagia CL-AP6T, followed by Pseudomonas xinjiangensis S3-3T (97.16â%), Pseudomonas sabulinigri J64T (97.15â%) and Pseudomonas xiamenensis C10-2T (96.47â%). Analysis of strain KBL-4-9T based on the three housekeeping genes, rpoB, rpoD and gyrB, further confirmed the phylogenetic assignment of the isolates. The DNA G+C content was 61.6âmol% (sd = 2.19). DNA-DNA hybridization with P. pelagia CL-AP6T, P. xinjiangensis S3-3T and P. sabulinigri J64T revealed 49.3â% (sd = 3.04), 41.2â% and 52.5â% (sd = 4.45) relatedness, respectively. The major cellular fatty acids of strain KBL-4-9T were C16â:â0, C12â:â0, summed feature 8 (C18â:â1ω7c and/or C18â:â1ω6c) and C17â:â0 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-4-9T 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 KBL-4-9T ( = JCM 19138T = CCTCC AB 2013069T = NRRL B-59988T).
ABSTRACT
OBJECTIVE: The aim of this study was to identify the microbiological characteristics of a Lysinibacillus strain isolated from storage liquid in the stems of Populus euphratica trees. METHODS: Bacterial morphology and cultivation characteristics were studied by conventional cultivation and dyeing method. Biochemical characteristics, fatty acid components, menaquinone, polar lipids, phylogenetic analyses of 16S rRNA, determination of (G + C) mol% content and DNA- DNA hybridization were studied by polyphasic taxonomic approach. RESULTS: Strain ML-64 is Gram-positive, endospore-forming and rod-shaped. Colonies are pale-yellow, circular and entire margin. Temperature range for growth is between 10 and 45 degrees C (optimum at 37 degrees C ). The pH range for growth is between 6. 0 and 9.0 (optimum at 7.0). NaCl concentration range for growth is between 0 and 6% (optimum 3% ). Cells were positive for lipid esterase, Arginine dihydrolase, urease and Voges-Proskauer test. No sugars were fermented in the API 50CH strips. L-Serine, Methyl Pyruvate, α-Keto-Butyric, Acetoacetic Acid were oxidized. Resistant to polymyxin b (30 µg), novobiocin (30 µg), peillin G (10 U). 16S rRNA gene sequence demonstrated that strain ML-64 was closely related to Lysinibacillus chungkukjangi 2RL3-2T (100%) , Lysinibacillus sinduriensis BLB-1T (99.1%). DNA-DNA relatedness were 82% and 50. 9% with Lysinibacillus chungkukjangi 2RL3-2T and Lysinibacillus massiliensis CIP108446T, respectively. The genomic DNA G + C content of strain ML-64 was 36. 8% (mol). Major fatty acids were iso-C,,, (55. 05% ) and anteiso-C15,0 (20. 70% ). The predominant menaquinone is MK-7. Based on the phenotypic phylogenetic and genotypic analyses, the strain ML-64 is concluded to represent a new mutant strain of the Lysinibacillus chungkukjangi species, GenBank accession number is KC609752. CONCLUSION: As an endophytic bacterium of Populus euphratica, genomic structure of the strain ML-64 was greatly differentiated from the closest strain L. chungkukjangi, and suitably adapted to the endophytic environment of Populus euphratica.
Subject(s)
Bacillaceae/isolation & purification , Populus/microbiology , Bacillaceae/classification , Bacillaceae/genetics , Bacillaceae/metabolism , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/metabolism , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/geneticsABSTRACT
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 °C (optimum, 28 °C), at pH 6.0-9.0 (optimum, pH 7.5) and in the presence of 0-3â% (w/v) NaCl with 1â% 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 97.2â% to Rhizobium rosettiformans W3(T), followed by Rhizobium nepotum 39/7(T) (96.5â%) and Rhizobium borbori DN316(T) (96.2â%). Phylogenetic analysis of strain K-38(T) based on the protein coding genes recA, atpD and nifH confirmed (similarities were less than 90â%) 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 48.4â%, 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 C18â:â1ω7c and/or C18â:â1ω6c; 57.2â%), C16â:â0 (13.6â%) and summed feature 2 (comprising C12â:â0 aldehyde, C14â:â0 3-OH/iso-C16â:â1 I and/or unknown ECL 10.928; 11.0â%). 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 K-38(T) (â=âCCTCC AB 2013068(T)â=âNRRL B-59990(T)â=âJCM 19159(T)).