高含量原粉生产菌株苏云金芽孢杆菌LX-7的研究

Study on the Strain LX-7 of Bacillus thuringiensis with High Level of Insecticidal Crystal Protein

从土壤中分离的苏云金芽孢杆菌LX-7高毒力菌株,利用单因子筛选和正交试验,得到其最佳培养基配方(g/L)为:玉米淀粉30,氮源A30,氮源D15,氮源E15,并对其发酵工艺和后处理工艺进行了优化,40000L发酵罐发酵制得原粉效价达到80000IU/mg以上,晶体蛋白含量达到13.2%。

The high toxicity strain of Bacillus thuringiensis LX-7 isolated from soil was studied in this paper. The optimum formula of the culture medium which containing 30 g/L corn starch, 30 g/L nitrogen source A, 15 g/L nitrogen source D and 15 g/L nitrogen source E was obtained from unifactor experiments and orthogonal experiments. Under the optimized conditions of fermentation and post-treatment, the titer of powder and content of insecticidal crystal protein produced in 40 m^3 fermentor had reached 80 000IU/mg and 13.2% respectively.