利用菌体生长限制效应的HBV DNA疫苗发酵工艺

Optimization of HBV DNA Plasmid Fermentation Process by the Strategy of Bacterial Growth Limitation

目的对HBV DNA疫苗工程菌的发酵工艺进行优化。方法首先通过摇瓶培养确定基础培养基组成,提高单位菌量的质粒表达量。其次,在40 l发酵阶段,通过溶氧反馈调节的补料方式产生生长限制效应,进一步获得高拷贝表达质粒的菌体。结果培养基优化后的工程菌DH5α/pS2S发酵最终可获得质粒304.99mg/l,质粒含量可达到2.40mg/g湿菌,超螺旋质粒DNA的比例达95%以上。结论已建立了在单位体积和单位菌量内高表达质粒HBV DNA疫苗工程菌的发酵工艺,为HBV DNA疫苗的工业规模化生产奠定了基础。

Objective To optimization of HBV DNA plasmid fermentation process. Methods The composition of batch medium was determined to increase plasmid copy number per bacteria by shaking flask test.In the fed-batch phase of 40l fermentation,the plasmid copy number was further increased by growth limitation strategy which is characterized by DO2 feedback feeding control. Results By using the optimized fermentation process,plasmid content from the fermentation harvest reached 304.99mg/l or 2.40mg/g bacteria,and the proportion of supercoiled plasmid DNA was higher than 95%. Conclusion The fermentation process was developed,with high copy number of plasmid both per liter and per bacteria.It laid a foundation of industrial scale production of the therapeutic HBV DNA vaccine.