重组戊型肝炎病毒衣壳蛋白工程菌的高密度培养

在10L发酵罐中对戊型肝炎病毒衣壳蛋白在重组大肠杆菌中表达发酵工艺进行了研究，用分批培养方法探讨了不同培养基、培养基中磷酸盐浓度和Mg^2＋浓度等因素对菌体生长与重组蛋白表达的影响；用分批补料培养研究了不同的补料工艺对菌体生长与重组蛋白表达的影响，同时对重组菌诱导时期、诱导持续时间以及不同诱导温度表达包含体在尿素溶液中的溶解性进行了研究。结果表明，在优化后的培养基中，磷酸盐浓度、Mg^2＋浓度分别为80mmol/L 与20mmol/L时菌体生长与表达效果较好；分批补料培养中，37℃培养9h菌体达到对数期中期(约45OD600)为适宜诱导时期，加入终浓度为10mmol/L IPTG后诱导5h，OD600达到80以上，重组蛋白表达量达到29.74％，为最适收获菌体时间；37℃表达的包含体80％以上溶解在4mol/L的尿素溶液中，最终浓度达到14mg/mL； 10L发酵罐中确定的发酵工艺参数在30L发酵罐中进行了放大培养，10L发酵罐中确定的发酵工艺参数在30L发酵罐上具有可放大性与重复性， 可以应用于工业生产。

Hepatitis E Virus Capsid Protein Production by High Cell Density Culture of Recombinant Escherichia coli

Production of Hepatitis E Virus capsid protein by high cell density culture in recombinant E. coli has been studied in 10L and 30L fermentors. The effects of different factors on growth and producing recombinant protein of E. coli have been studied by batch culture, such as different media, the ratio of phosphate and Magnesium sulfate. Comparison of fermentation performance for recombinant E. coli in different fed-methods culture has been investigated by fed-batch culture. The effects of inducing at different stages of growth and time of inducing on growth and producing recombinant protein, also obtained by fed-batch culture. At last, the solubility of inclusion body in different urea concentrations also has been obtained by fed-batch culture. The results show that the concentration of phosphate and Magnesium sulfate in the optimal media is 80mmol/L and 20mmol/L in batch culture respectively, that induction with 1.0mmol/L IPTG at mid log phase (about 45 OD at 600nm) is suitable for growth and recombinant protein expression, the cells were approaching stationary growth phase and the maximum cell OD at 600nm of 80 was achieved in 5h of fed-batch culture, and the expression level is 29.74%. The results also indicate that the solubility of inclusion body in 4mol/L urea solution induced at 37 degrees C reaches 14mg/mL, over 80% inclusion body was resolved. The culture process achieved in 10L fermentor could be successfully scaled up to 30L fenmentor with good reproducibility.