苏云金芽胞杆菌Bt 0601发酵条件的优化研究

Optimization of Fermentation Conditions of Bacillus thuringiensis Strain Bt 0601

应用正交实验和单因子实验,结合杀虫毒力测定,对携带杀虫基因cry1Ac和虎纹捕鸟蛛毒素基因Hwtx-I的苏云金芽胞杆菌工程菌Bt 0601的发酵工艺条件进行研究。实验获得的苏云金芽胞杆菌Bt 0601工程菌的最佳发酵条件为:发酵初始酸碱度控制在pH 7.5、发酵温度(30±0.5)℃、转速200 r/min、通气量为30 mL/300 mL,接种量为4%,培养44 h。此外,本文还对Bt 0601菌株在30 L发酵罐中的发酵特性进行了研究,摸索了通气量对其大罐发酵的影响,确定大罐发酵的最佳通气量为1.75 L/min。

The optimization of fermentation conditions of recombinant Bacillus thuringiensis strain 0601, which carries crylAc and huwentoxin-Ⅰ gene, was studied by the orthogonal test, single factor test and bioassay. The results indicated that the best fermentation conditions of Bt 0601 strain were as follows： 7.5 of initial pH value, （30±0.5） ℃ of temperature, 200 r/rain of rotational speed, 30 mL/300 mL of ventilation, 4 % of inoculum volume, 44 h of cultivation. Moreover, the fermentation characterization and air flow rate of Bt 0601 strain in 30 L fermentator were also studied, and the most optimum air flow rate was 1.75 L/min.