重组G蛋白基因工程菌高密度发酵研究

目的]探索基因重组工程菌高密度发酵工艺,为得到高浓度和高产量的链球菌(Streptococcus)G蛋白(SPG)奠定基础。方法]通过一级摇瓶、二级种子罐培养,以及将菌种转接到发酵罐并进行分批补料高密度培养,探讨了IPTG加入量等条件对发酵的影响,考察了接种量、氧气、pH、培养方式等发酵工艺。结果]高密度发酵能得到至少80 g/L的菌体,最高达到150 g/L,每升发酵液可得到1 g的SPG。SPG高密度发酵的生产条件为:接种量10%,通气量1 vvm,溶氧控制在30%～45%,发酵过程控制pH 7.0～7.2,IPTG的诱导浓度为0.2 mmol/L,时间为4 h,发酵后SPG总蛋白能达到菌体蛋白的20%以上。结论]利用该生产工艺可得到高浓度菌体和高产量SPG。

Study on the Conditions of High Cell Density Fermentation for the Engineering Bacteria Expressed Recombinant Protein SPG

Objective] To explore the high cell density fermentation for the engineering bacteria,so as to lay foundation for obtaining high-concentration and high-yield SPG.Method] The bacteria were transferred to a fermenting cylinder for a fed-batch high-density culture,the fermentation factors of IPTG dose,oxygen,pH and culture methods were studied.Result] Under high cell density fermentation,80-150 g/L bacteria were obtained,per liter of fermentation liquid contained 1 g SPG.The fermentation conditions of SPG were 10% IPTG dose,1 vvm ventilation,30%-45% dissolved oxygen,7.0-7.2 pH,0.2 mmol/L IPTG concentration,and 4 h time,after fermentation,the total protein in SPG accounted for above 20% of the bacterial protein.Conclusion] High-concentration and high-yield SPG could be obtained through this high cell density cultivation.