用凝胶电泳方法鉴定苏云金芽孢杆菌溶源性菌株

Using Gel Electrophoresis to Determine Lysogenic Bacillus thuringiensis

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。

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 resuhs 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.