苏云金杆菌4.0718高毒力杀虫菌株发酵条件的研究

Study on Fermentation Conditions of the High Toxic Insecticides Strains of Bacillus thuringiensis

在对苏云金杆菌 (Bacillusthuringiensis)高毒力杀虫菌株 4 0 718产毒单因子培养条件试验的基础上 ,采用正交设计试验培养和结合杀虫毒力测定的方法 ,对该菌株产毒的发酵条件进行了研究。结果表明 :在摇瓶发酵培养时 ,培养基C/N比为 3 7,发酵起始 pH为 7 8～ 8 0 ,发酵温度为 (2 9± 1)℃ ,15 0r/min摇瓶培养 43～ 44h ,接种量为 6%～ 8%时 ,该突变菌株杀虫毒力与原始菌株相比提高了 7 5倍。连续传代培养 10次 。

The fermentation conditions of a high toxic mutant strain 4 0718 of Bacillus thuringiensis are determined with orthogonal experiment and bioassays of insecticidal activity, based on single factor's culture conditions It reveals that ratio of carbon to nitrogen (C/N) is 3 7∶1, initial pH 7 8～8 0, temperature (29±1)℃, rotary agitation at 150 r/min for 43～44h and inoculum 6%～8% It also shows that the mutant strain's toxicity is 7 5 times higher than that of its parental strain, and heredity of the high insecticides virulence is stable with ten times continuous transfer of culture