苏云金芽孢杆菌伴孢晶体的制备

Preparation of Crystal Protein from Bacillus Thuringiensis

采用液体培养和固体培养两种不同的方法培养苏云金芽孢杆菌,并比较了高速离心法、透析法以及等电点沉淀法三种纯化方式对伴孢晶体的纯化效果。镜检观察结果表明,固体培养更有利于菌体产生伴孢晶体。利用棉铃虫进行的生物测定结果表明,透析法纯化所得伴孢晶体生物效价较高,达到150000IU.mg-1。扫描电镜观察结果显示,透析法纯化所得伴孢晶体纯度较高且形态完整。

Bacillus thuringiensis （Bt） was cultured by two kinds of medium,and then was treated by highspeed centrifugation method, dialysis method and isoelectric point deposition method, respectively. The result of microscopical study indicated that solid medium was better for producing crystal protein. Through the bioas- say result for Helicoverpa armigera dialysis method was proved to be the best purification method with product titer of 150 000 IU · mg^-1. The SEM result indicated that the crystal protein obtained by dialysis method had high purity and complete shape.