生防细菌HMQ20YJ04发酵条件优化及其对番茄灰霉病的效果评价

Optimization of Fermentation Conditions of Biocontrol Bacteria HMQ20YJ04 and Evaluation of Its Effect on Botrytis cinerea

菌株HMQ20YJ04是从甘肃民勤盐碱土壤中分离筛选的对多种植物病原真菌具有较强抑菌活性的拮抗细菌。为提高其发酵液的防控效果,以发酵液活菌数作为检测指标,采用单因素试验、正交试验、Plackett-Burman试验和响应曲面法对发酵培养基组分和摇瓶发酵条件进行筛选和优化。结果表明,最佳发酵培养基组分配比为可溶性淀粉5 g/L、酵母提取物10 g/L、MgSO_(4)·7H_(2)O_(5) g/L、NaCl5 g/L,最佳发酵条件为转速200 r/min、接种量5%、温度32℃、时间60 h、初始pH6.5。温室盆栽防控番茄灰霉病试验结果表明,该菌株的发酵液对番茄灰霉病具有良好的防控效果,防效为63.03%。研究结果为枯草芽胞杆菌菌株HMQ20YJ04的菌剂研发及番茄灰霉病的生物防治提供了依据。

Strain HMQ20YJ04 is an antagonistic bacterium isolated and screened from saline-alkali soil in Minqin,Gansu Province,which has strong antifungal activity against various plant pathogenic fungi.In order to improve the control effect of fermentation liquid,the number of viable bacteria in fermentation liquid was used as the detection index,the fermentation medium components and shake flask fermentation conditions were screened and optimized by single-factor test,orthogonal test,Plackett-Burman test and response surface method.The results showed that the optimal composition of fermentation medium were soluble starch 5 g/L,yeast extract 10 g/L,MgSO_(4)7H_(2)O 5 g/L and NaCl 5 g/L and the optimal fermentation conditions were rotation speed 200 r/min,inoculation amount 5%,temperature 32℃,cultivation time 60 h and initial pH 6.5.The results of pot experiments in greenhouse showed that the fermentation liquid of strain HMQ20YJ04 had a good control effect on tomato gray mold,with the control effect of 63.03%.The above results provided a basis for the research and development of Bacillus subtilis strain HMQ20YJ04 agent and its application in biological control of tomato gray mold.