从大豆植株中分离到一株具有广谱抗菌活性的拮抗细菌,命名为XZ-2。抑菌活性测定显示XZ-2对甘薯黑斑病菌、大蒜叶枯病菌等8种植物病原真菌均具有较强的抑菌活性,抑菌直径均在20 mm以上。采用分光光度法绘制了XZ-2的生长曲线,结果显示该菌株在LB液体摇培12 h时基本达到对数生长期,该生长曲线的绘制为后期XZ-2的活性物质发酵条件优化奠定了基础。通过PCR扩增16Sr DNA片段并采用MEGA 6.0构建系统发育进化树,初步将该菌株鉴定为多粘类芽孢杆菌。 An antagonistic bacterium with broad spectrum antibacterial activity was isolated from soybean plants and named as XZ-2. The results of antibacterial activity test showed that XZ-2 had strong antibacterial activity against eight plant pathogenic fungi, such as Alternaria solani and Botryosphaeroides, with antibacterial diameters of more than 20 mm. The growth curve of XZ-2 was drawn by spectrophotometry. The results showed that the strain reached the logarithmic growth phase when LB liquid was cultured for 12 h, and the growth curve was laid for the optimization of the fermentation conditions of the active material of XZ-2 basis. The 16Sr DNA fragment was amplified by PCR and phylogenetic tree was constructed by MEGA 6.0. The strain was identified as Bacillus polymyxa.