【摘要】 目的:开发具有特异性杀虫谱特性的Bt菌新株系,促进Bt菌制剂的更新换代,减缓抗性发生。方法:在前人对摇瓶培养研究的基础上.通过改变培养基成分、通气量和pH等操作条件,检测不同条件对菌体生长量、芽孢及伴孢晶体形成的影响,对中国Bt Ken—Ag这一新的优良菌株发酵罐间歇发酵的工艺条件进行研究。结果:中国Bt Ken—Ag 发酵罐发酵最佳工艺条件:发酵温度维持30℃,发酵前期,控制pH为7.0,用较大的通气量1∶2. Ovvmin;发酵后期不控制pH,并适当减小通气量为1∶0. 5vvmin。这样就使得发酵前期菌体达到75亿/ml的较高浓度,发酵后期则实现了菌体向芽孢转化的高转化率98％以上。结论:初步得出适于该菌发酵的最佳工艺,为该菌制剂的生产应用提供可靠依据。更多还原

【Abstract】 Objectives: Exploits new strains of Bt for the idiosyncratic insecticides to make replacement and slow down the insect -resistance. Methods: On the basis of fermentation in shaking flasks, studies on the process of Chinese Bt Ken - Ag. The effects on the growth and sporulation were examined, through changing the bioreactor operations, such as the composition of culture medium, aeration and pH. Results: The optimum process is 30℃ , pH7. 0, aeration 1: 2. 0vvmin in the earlier stage and no controlling pH,aeration 1: 0. 5vvmin in the later period. The number of cell reached 7. 5 × 10E9/ ml and spore forming rate is more than 98%. Conclusions: The optimum process, obtained from the fed -batch cultivation, provides basis for producing and applying the preparation of Chinese Bt Ken -Ag.更多还原