The isolated plasmid PMPR4. pMPR8 pMPR16. harboring the neutral protease gene were used to transform four B. subtilis strains ASl. 398, ML,DB104 and BG 2036. The protease activity of transformatnts showed a significant increase.

• 用含有中性蛋白酶基因的重组质粒pMPR4、pMPR8和pMPR16转化BacillussubtilisBG2036，BacillussubtilisAS1.；398和BacillussubtilisML，对转化菌产生的蛋白酶活性分析表明：三个重组质粒的导入，均使宿主菌的酶活性有大幅度的提高。