短小芽孢杆菌DST27发酵培养基及发酵条件的优化

Optimization of fermentation medium and conditions for Bacillus pumilus DST27

[目的]通过优化生防菌株短小芽孢杆菌DST27发酵培养基及发酵培养条件,为后期该菌株的开发和应用提供基础。[方法]通过单因素筛选、Plackett-Burman试验和响应面分析法,以菌体生长量和对尖孢镰刀菌的抑菌活性为指标,优化DST27发酵培养基及发酵培养条件。[结果]最佳发酵培养基为1.35%葡萄糖、1%酵母粉和0.5%CaCl2;最佳发酵条件为装液量20%、接种量5.40%、初始pH 7.28、温度28℃和转速180 r/min,在此培养条件下DST27的OD600为2.256,抑菌率为78.65%,与模型预测值81.42%相近,较优化前提高了22.06%。[结论]该试验优化了DST27发酵培养基及发酵条件,为今后该菌剂生产工艺及开展防治提供理论依据。

[Aims]This study aims to establish a foundation for the later development and use of the biocontrol strain Bacillus pumilus DST27 by optimizing the fermentation medium and circumstances.[Methods]Based on single factor test,Plackett-Burman test and response surface analysis,the fermentation medium and conditions of DST27 were optimized with the bacterial biomass and the antifungal activity against Fusarium oxysporum as indicators.[Results]The optimal medium for liquid fermentation of strain DST27 was 1.35%glucose,1%yeast powder,and 0.5%CaCl.The optimal fermentation conditions were as follows:liquid-loading rate 20%,inoculation amount 3%,pH 7.28,temperature 28℃,time 60 h,and rotating speed 180 r/min.The ODoo of DST27 was 2.256 under these cultivation circumstances,and the antifungal rate was 78.65%,which was similar to the predicted value of 81.42%in the model,and had increased by 22.06%compared to that before optimization.[Conclusions]This experiment optimized the fermentation medium and conditions of DST27,providing a theoretical basis for the production process of this bacterial agent and prevention with it in the future.