用凝胶电泳方法鉴定苏云金芽孢杆菌溶源性菌株

根据原噬菌体的可诱导性,将苏云金芽孢杆菌(Bacillus thuringiensis,简称B t)培养液用丝裂霉素C(MMC)诱导,诱导液经高速离心除菌和2.5×SDS-EDTA染料混合液处理后,琼脂糖凝胶电泳检测有无DNA带,以确定菌株的溶源性。实验证明,该DNA为溶源菌诱导出的噬菌体DNA,而非溶源菌以同样方法不能获得DNA。用此方法,可作为鉴定B t溶源性菌株的一个手段,有助于B t工业发酵中噬菌体污染的预防。

Using Gel Electrophoresis to Determine Lysogenic Bacillus thuringiensis

Considering the feasibility that prophages could be induced, we used mitomycin C(MMC) to induce Bacillus thuringiensis (commonly referred to as Bt) strains used in this study . Firstly , the strains induced by MMC were centrifuged and the supernatants were treated with 2.5 SDS-EDTA. And then, they were put into the 0.7% agarose-gel electrophoresis to test whether there were DNA bands or not . The results of agarose-gel electrophoresis and double-layer plates indicated that the DNAs were from lysogenic Bts, not from no-lysogenic Bts. By using this method ,we could determine lysogenic Bts, and it is important for protecting Bts from phage infection during the process of fermentation .