表达人肝细胞生长因子突变体——NK4工程菌的发酵工艺研究

目的　建立重组NK4融合基因工程菌的发酵工艺。方法　采用锥形瓶、发酵罐发酵 ,对工程菌生长和表达条件如pH、诱导时间及诱导剂浓度等方面进行优化。确定其最佳诱导表达条件 ,在 15L自控发酵罐中进行分批补料培养。结果　在 15L发酵罐进行工程菌发酵 ,菌体收获量湿重可达 2 4 .6g L± 0 .98g L ,目的蛋白的表达量保持在菌体总蛋白的 5 0 %左右 ,发酵时间为 11h。结论　建立了周期短、产率高且稳定可靠的发酵工艺。

Fermentation Procedure for Recombinant E. coli Strain Expressing NK4, A Mutant of Human Hepatocyte Growth Factor

Objective To develop a fermentation procedure for recombinant E.coli strain expressing NK4 gene.Methods The recombinant E.coli strain was inoculated into Erlenmeyer flasks and incubate d in a fermentor,and the conditions for the growth and expression of the recombi nant strain,such as pH value,time for induction and IPTG concentration,were opti mized.Under the optimal condition,the recombinant strain was incubated in a 15 L automatically-controlled fermentor by fed batch incubation.Results The optimal pH value,time for induction and IPTG concentration were 7 1, 5 h and 1 mmol/L respectively.By the optimal procedure,the bacteria with a wet w eight of 24 6±0 98 g/L were harvested,and the expressed product contained abo ut 50% of total somatic protein.The time duration for fermentation was 11 h. Conclusion A stable and reliable fermentation procedure,with a shor t production cycle and a high yield,was developed.