nisRK和nisIRK超表达对nisin合成的影响  

Effect of Over-expression of nisRK and nisI-RK on nisin Production

作　　者：汪蕊[1] 杜超[1] 左芳雷[1] 李平兰[1] 陈尚武[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院食品科学与工程系,北京100083

出　　处：《生物技术》2013年第6期30-37,共8页Biotechnology

摘　　要：目的:构建表达载体pMG76e-nisRK、pMG76e-nisI-RK以及含有nisI、nisR、nisK基因的载体pmsp3535H4,合成重组菌,分析nisin合成基因簇中的nisRK和nisI-RK超表达对nisin生物合成的影响。方法:将nisRK、nisI-RK基因克隆与表达载体pMG76e酶切后连接转化,并通过Bio-Rad Gene Pulsor电穿孔法将重组质粒载体以及pmsp3535H4转入Lactococcus Lactis N401菌株中,分别得到3株质粒转化转基因菌株N401A、N401B和N401C。对比工程菌和原始产生菌的生长状态及Nisin Z产量。结果:成功构建重组菌株,与起始菌株N401相比,N401A、N401B、N401C的生长速度、生物量以及发酵液的pH值没有显著差异,而转基因菌株的Nisin Z产量提高了45%左右。其中N401C的Nisin Z产量提高程度略低于另两株工程菌。结论:nisRK与nisIRK超表达对Nisin生物合成能到的明显提高具有同等作用。Objective：Constructed expression vector which contained two -component auto -regulatory system consisting of nisRK and the immunity gene nisl of Nisin Z and pmsp3535H4 containing the gene nisl and n/sRK, and recombinated new strains. In this study, nisin Z bi- osynthesis in Lactococcus lactis N401 was investigated by overexpression of genes n/sRK and nisl- RK. Method ：The gene of nisRK, nisl- RK was cloned into pMG76e vector. The expression vector pMG76e - nisRK, pMG76e - his[ - RK and pmsp3535H4 were expressed in/xzc- tococcta~ lactis N401 with Bio - Rad Gene Pulsor. Result：The new expression vector was constructed successfully. A similar growth profile was obtained from all the three type transformant strains of L. lactis obtained. The production of Nisin Z overexpressing nisRK, nisl -RK was improved by 45% compared to the start strain N401. Conclusion ：The results indicated the similar contribution of the over expressing nisRK and nisl - RK for the nisin production by L. lactis.

关 键 词：乳酸乳球菌 NisinZ生物合成 过量表达 

分 类 号：Q935[生物学—微生物学]