毕赤酵母高密度发酵工艺的研究

High Density Fermentation Control of Pichia pastoris

高密度发酵是毕赤酵母提高蛋白表达量的一种重要策略,发酵工艺是高密度发酵的一个重要因素。采用下列措施均可以有效地提高表达水平:调节基础培养基,采用变pH和变温发酵,提高DO,选择最适的诱导前菌体密度和比生长速率并降低甘油初始浓度和采用分段式指数流加进行调控。选择合适的甲醇补料策略:甲醇限制补料(MLFB)、氧气限制补料(OLFB)、甲醇不限制补料(MNLFB)和温度限制补料(TLFB)。采用两种方式调控补料:诱导阶段菌体生长时,甲醇比消耗速率(qMeOH)为0.02-0.03gg-1h-1,而菌体不生长时,qMeOH采用较高值。

One of the important strategies for improving recombinant protein expression in Pichia pastoris is optimizing control during the high density fermentation process. Some fermentation control has been used and got obviously higher expression level： optimization of basal salt medium composition; using two stage pH and two stage temperature control during cell growth and induction stage; appropriately increasing dissolved oxygen; selecting optimal cell density prior to induction （ CW^PTI ） and specific growth rate prior to induction （ μPTT ）, using limit amount of initial glycerolin the basic media and feeding it during the fermentation with exponential fed-batch Model, selecting appropriate methanol feeding strategy by methanol -limited feeding batch （ MLFB ）, limited feeding batch （ OLFB ）, methanol -unlimited feeding batch （ MNLFB ） or temperature -limited batch （TLFB） . Some research suggested that the expression level of the recombinant protein increase after optimizing the fermentation control.