【摘要】 新秀丽小杆线虫(Caenorhabditis elegance)是一种模式生物,能够在室内培养。研究采用大肠杆菌(Escherichia coli)饲养,获得大量虫源,通过观察该线虫对不同Bt菌株产生毒力反应的情况,筛选含有毒力的Bt菌株。经筛选获得6个菌株的伴孢晶体与新秀丽小杆线虫进行毒性比较,野生菌株Bt-010杀虫快速而持久,毒力强,作用时间大约在36h左右,测得其理想的LC50为0.498μg/mL。初步纯化其毒性蛋白,发现其主要作用成分是为25～35kD的蛋白。DNA Ladder检测发现,在这个毒性蛋白的作用下线虫DNA同作用前没有区别,证明这个毒性蛋白不象化学农药能对线虫的DNA造成损伤。更多还原

【Abstract】 Caenorhabditis elegance is one of the model organisms that can be raised with Escherichia coli in laboratory. Crystal proteins from Bacillus thuringiensis are pore-forming toxins used as insecticides around the world. A collection of Bt strains were screened for comparing their toxic activity to nematodes. Six strains were identified with significant toxicity to the adult nematodes in vitro. By assaying their toxicity on free-living nematodes for 36 h,the LC50 of the nematicidal toxins achieved 0.498 μg/mL . It’s concluded that Bt crystal proteins have potential to control nematodes. Toxic proteins were purified crudely by sulfate and the sizes were estimated by comparison with protein standards. DNA ladder survey showed that the toxic protein, unlike chemical pesticides, would not damage nematodes DNA .更多还原