响应面法优化沃柑采后青霉病拮抗细菌贝莱斯芽孢杆菌wr8的发酵条件

Optimization of fermentation conditions of Penicillium sp.antagonistic bacterium Bacillus velezensis wr8 in postharvest citrus by response surface method

青霉(Penicillium sp.)是造成沃柑采后腐烂的重要病原菌之一,为探究青霉拮抗菌贝莱斯芽孢杆菌(Bacillus velezensis)wr8的适宜发酵条件,在单因素试验基础上,以青霉抑菌圈直径为响应值,利用响应面分析法对贝莱斯芽孢杆菌wr8的培养条件进行优化,得到其最优的发酵条件为蛋白胨10.0 g/L、牛肉膏9.5 g/L、酵母粉5.0 g/L、氯化钾5.0 g/L、种龄7.0 h、装液量150 mL/250 mL、接种量2.0%、初始pH值6.5,优化后菌株wr8对青霉产生的抑菌圈直径为(20.42±0.14)mm,是未优化前的1.63倍。该研究为生物防治沃柑采后腐烂技术的开发与利用提供了应用基础。

Penicillium sp.is one of the popular pathogens causing postharvest rot of citrus.In order to explore the suitable fermentation conditions of Bacillus velezensis wr8 that is antagonistic Penicillium sp.,the culture conditions of B.velezensis wr8 was optimized by response surface methodology using inhibition zone diameter as the response value based on single factor tests.The optimum fermentation conditions were obtained as follows:peptone 10.0 g/L,beef extract 9.5 g/L,yeast extract 5.0 g/L,potassium chloride 5.0 g/L,seed age 7.0 h,loading volume 150 ml/250 ml,inoculum 2.0%,and initial pH 6.5.The diameter of inhibition zone produced by strain wr8 against Penicillium sp.after optimization was(20.42±0.14)mm,which was 1.63 times that of before optimization.The study provided an application basis for the development and utilization of the biocontrol technology of citrus rots after harvesting.