表达重组葡激酶-水蛭素融合蛋白的大肠杆菌工程菌的高密度培养

采用溶氧反馈的分批培养流加补料的方法高密度培养重组大肠杆菌BL21(DE3)生产重组葡激酶-水蛭素融合蛋白。通过摇瓶培养对菌种和培养条件的初步筛选，采用溶氧反馈的流加补料策略，进行了5L发酵罐的合成培养基和复合培养基的发酵工艺的研究。通过对培养条件的不断优化，重组葡激酶-水蛭素融合蛋白在大肠杆菌BL21(DE3)里得到了高效表达，菌体密度最终达到115g/L(WCW)以上，可溶性重组融合蛋白占菌体总蛋白的30%以上，含量约为1.1~1.2g/L。5L发酵罐的发酵工艺参数在40L发酵罐中进行了放大培养，结果表明该工艺能有效的放大，可适用于工业生产。

High Cell Density Cultivation of Recombinant Escherichia coli for Production of Fusion Protein Staphylokinase-Hirudin

Recombinant fusion protein staphylokinase-hirudin has been produced by adopting the dissolved oxygen feed-back fed-batch with the high cell density cultivation strategy in E.coli BL21(DE3). After selection of the strain and the preliminary optimization by flask cultivation, the fermentation was performed with comparing the differences between defined medium and complex medium in 5L fermentor. With the optimization of the cultivated conditions, the recombinant fusion protein staphylokinase-hirudin was over-expressed in E.coli BL21(DE3), and the final cell density reach 115g wet cell weight per liter, the target protein is about 1.1~1.2g/L accounting for more than 30% of the total protein. The culture process in 5L fermentor was performed on 40L fermentor successfully, and indicated that the process was easy scalable.