论文部分内容阅读
选用土壤新分离株Ｓ１８－４为供体菌，以ＰＨＴ３１０１穿梭质粒为载体，载体和供体ＤＮＡ用Ｐｓｔｌ酶切后进行连接，用电激法将重组质粒转入苏云金芽孢杆菌无晶体突变株Ｂｔｋ·ＢＥ２０中。经ＳＤＳ－ＰＡＧＥ蛋白电泳及扫描电镜观察，证明δ－内毒素基因得到了表达，并具有很高的表达量。生物测定结果显示，重组株对夜蛾科幼虫具有比野生株Ｓ１８－４更强的杀虫毒性。
The new soil isolate S18-4 was used as donor bacterium, PHT3101 shuttle plasmid was used as vector, vector and donor DNA were digested with Pstl, then the recombinant plasmids were transferred into Bacillus thuringiensis strain Btk without electroporation BE20. The SDS-PAGE protein electrophoresis and scanning electron microscopy showed that the δ-endotoxin gene was expressed and had a high expression level. Bioassay results showed that the recombinant strains had stronger insecticidal toxicity to the noctuid larvae than the wild strain S18-4.