室内条件下,分别测定了苏云金杆菌Bt 00-50-5菌株液体和固体发酵物对南方根结线虫的毒力效果.结果显示,牛肉膏蛋白胨液体发酵法在72 h所得上清液的毒性最高,南方根结线虫死亡率达到99.0%,而固体麸皮发酵物对线虫的最高毒性为发酵8 h,南方根结线虫死亡率为89.0%.液体发酵上清液经葡聚糖凝胶G-75柱层析分离,柱下物在280 nm处的吸收值呈现出4个峰I、II、III和IV,其值0.601,1.475, 1.641和0.392,其中峰II、III、IV处收集的蛋白对南方根结线虫有毒杀作用,分子量最小的IV蛋白杀线虫活性最高.上清液天然聚丙烯酰胺凝胶电泳分离杀虫蛋白结果显示6条清晰蛋白带,其中37 kDa 蛋白含量最多.%Nematocidal activities of fermentation products of Bacillus thuringiensis 00-50-5 culture using a liquid or solid medium in the lab was investigated.The results showed that the supernatant collected from the 72-h-fermentation on abeef-extract broth showed a 99.0% lethality on Meloidogyne incongnita;while that from the 8-h-fermentation on a bran-based medium, 89.0%.The supernatant collected from the liquid fermentation was subsequently subjected to a Sephadex G-75 column chromatography separation.Four peaks with the absorbance of 0.601, 1.475, 1.641 and 0.392 at 280nm were present.The bioassay on them indicated that the proteins found at Peak II, III, and IV were toxic to M.incognita, and among them, the one from Peak IVwith the smallest molecular weight exerted the greatest nematocidal effect onthe parasite.The native-PAGE profile on the supernatant showed 6 visible protein bands including a 37 kDa protein, which was the highest in amount.
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