猪流行性腹泻抗原基因在乳酸菌中的表达及优化

目的：优化猪流行性腹泻抗原基因COE在乳酸乳球菌中的表达。方法：将表达猪流行性腹泻抗原基因COE的重组乳酸菌活化,酶切鉴定其稳定性,然后设计实验分别从pH值、温度、Nisin浓度、诱导时间、菌体密度等条件对COE表达进行优化,SDS-PAGE检测表达效果。结果：COE在乳酸乳球菌中的最佳表达条件为pH 7.0、T（温度）=30℃、Nisin=2ng/mLt、（诱导时间）=4h和OD600=0.5,在以上条件下相对表达量分别达到了15.48%、15.05%、15.82%、14.72%和20.47%。在最佳表达条件下得到SOE的相对表达含量达到21%。结论：COE重组质粒稳定,其在乳酸菌中经优化表达后可为今后研制猪流行性腹泻乳酸菌疫苗提供数据。

Expression and Optimization of Porcine Epidemic Diarrhea Virus Gene in Lactococcus lactis

Objective: To optimize expression of COE gene from porcine epidemic diarrhea virus(PEDV) in Lactococcus lactis.Method: The recombinant Lactococcus lactis that was inserted COE gene of PEDV was activated followed by identification its stability by digestion with endoenzyme.Then the COE gene was expressed and optimized from several aspects including different pH value of the medium,induction temperature(T),concentration of Nisin,induction time(t) and cell density.SDS-PAGE was processed to detect the expression.Result:The optimum expression condition results were shown for COE in Lactococcus lacti was pH 7.5,T 30℃,Nisin 2ng/mL,t 5h and OD_(600) 0.5,and the comparative expressing content under above condition reached to 15.48%,15.05%,15.82%,14.72% and 20.47%,respectively.Under the optimum expression condition the comparative expressing content of SOE reached to 21% in Lactococcus lactis.Conclusion: The recombinant COE plasmid was steadily existed in Lactococcus lactis and the optimization of expressing COE will supply new data to study engineering vaccine of PEDV later.