中文摘要：

【目的】从胡杨茎秆液中分离得到的一株菌株ML-64,对其进行微生物学特性的分析。【方法】通过细菌培养和染色的方法进行了形态和培养特征的检测,使用多相分类学方法测定菌株的各项生理生化指标,脂肪酸组分、醌组分、极性脂类型、16S rRNA基因系统发育分析、（G＋C）mol%含量的测定和DNA-DNA杂交分析。【结果】菌株ML-64为革兰氏阳性菌,杆状,产生芽孢。菌落为圆形,淡黄色,表面光滑。菌株生长温度范围为10-45℃（最适37℃）,p H范围为7.0-9.0（最适p H7.0）,Na Cl浓度范围为0-6%（W/V）（最适0-2%）。菌株ML-64的类脂酯酶,精氨酸双水解酶,脲酶活性和VP-实验为阳性。在API 50CH酶活性检测实验中菌株不能发酵任何糖类。可利用的碳源有：L-丝氨酸,丙酮酸甲酯,α-酮-丁酸,乙酰乙酸。对多粘菌素B（30μg）、新生霉素（30μg）、青霉素G（10 U）不敏感。16S rRNA基因序列分析结果表明,菌株ML-64T与Lysinibacillus chungkukjangi 2RL3-2T,Lysinibacillus sinduriensis BLB-1T有密切亲缘关系。相似率分别为100%和99.1%。菌株ML-64与Lysinibacillus chungkukjangi 2RL3-2T和Lysinibacillus massiliensis CIP108446T之间的杂交率分别为82%和50.9%。基因组DNA（G＋C）mol%含量为36.8%。菌株ML-64优势脂肪酸类型为iso-C15：0（55.05%）和anteiso-C15：0（20.70%）,醌组分类型是MK-7。【结论】基于表型特征、遗传型特征和系统发育分析,将菌株定为Lysinibacillus chungkukjangi的新变种,获得序列注册号为KC609752。胡杨内生菌ML-64的基因组结构已与最近源菌株L.chungkukjangi产生了较大的分化,选择性地适应了胡杨内生环境。

英文摘要：

[ 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 ℃ （optimum at 37 ℃ ）. The pH range for growth is between 6.0 and 9.0 （optimum at 7.0）. NaC1 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 （30μg）, 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-C15：0 （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