导向性人干扰素α2a工程菌的高密度发酵

High cell density fermentation of engneering E. coli expressing tumor targeted interferon-α2a

目的 :优化大肠杆菌表达导向性人干扰素α2a的中试发酵工艺 ,以获得工程菌的高密度发酵和目的蛋白的高表达 .方法 :采用发酵罐发酵 ,对影响工程菌生长和目的蛋白表达的条件 ,如pH值、活化时间、诱导时间、溶氧范围及补料流加方式等进行优化 .结果 :根据优化条件 ,连续三批重复发酵10L工程菌 ,最终菌体密度均达A60 0nm2 5～ 30 ,菌体获得量均可达湿重 5 0g/L以上 ,目的蛋白表达量均为 3.2× 10 9U/L以上 .结论 :此发酵工艺具有周期短、产量高以及重复性稳定性好的特点 ,为下游纯化和进一步大规模生产奠定基础 .

AIM: To optimize the pilot-scale fermentation procedure of E.coli producing tumor targeted human IFN-α2a and to obtain high cell density and high level expression of the aim protein. METHODS: The effects of the rang of pH, dissolved oxygen, culture time, induction time and the manner of feeding were analyzed with 10 L of fermentation tank. RESULTS: Under the established conditions, we performed a three-time repeated fermentation. The final cell density was A 600 nm 25-30 and more than 50 g of wet bacteria per liter could be obtained. The expression level of recombinant protein was higher than 3.2×10 9 U/L. CONCLUSION: The results show that the established fermentation procedure is stable, of short cycle and with high expression, which lays the basis for further purification and large-scale production of IFN-α2a-NGR.