重组人胰岛素样生长因子-Ⅰ工程菌高密度发酵工艺优化

目的优化表达重组人胰岛素样生长因子-Ⅰ(IGF-Ⅰ)工程菌的高密度发酵条件。方法考察培养基以及诱导时机、诱导剂量和诱导时间对蛋白表达的影响;用自控发酵罐进行分批补料培养实验,确定优化工艺条件。结果以2×YT+0.5%葡萄糖为发酵培养基,经0.8 mmol/L IPTG(异丙基-β-D-硫代半乳糖苷)诱导5 h,通过pH-stat反馈补料方式实现工程菌高密度发酵与目的蛋白高效表达,每1 L发酵液收获干菌体50.1 g,IGF-Ⅰ含量达5.25 g/L。结论建立了IGF-Ⅰ工程菌优化的高密度发酵工艺,为IGF-Ⅰ的下游纯化和工业化生产奠定了基础。

Optimization of high cell-density fermentation procedure of recombinant human insulin-like growth factorⅠin E.coli

Purpose To investigate the optimal high cell-density fermentation procedure of recombinant human insulin-like growth factorⅠ(IGF-Ⅰ)in E.coli.Methods 3 types of media,induction time and IPTG concentration have been analysed.To explore optimal fermentation conditions for expressing the recombinant protein,fed batch fermentation was carried out with autocontrol fermentor.Results Cultivated in 2×YT+0.5% glucose medium,induced by 0.8 mmol/L IPTG for 5 h,controlling dissolved oxygen and by pH-stat feeding solution,high cell-densityand high protein expression were achieved.Under the established conditions,50.1 g dry cell weight(DCW)/L could be obtained,and 5.25 g/L IGF-Ⅰwas achieved.Conclusion The established high cell-density fermentative procedure has provided a useful base for further purification and large scale production of IGF-Ⅰ.