After Bacillus thuringiensis some strains are treated with Diethylfu-1phur ( DES ) , the mutants of colony with cell morphology, and produced black pigment are gained.

• 用硫酸二乙酯(DES)处理苏云金杆菌CT-43菌株,得到了菌落形态、菌形和产生褐色素三种类型的突变株。