重组质粒DNA D-GPEi工程菌发酵工艺的优化

目的优化重组质粒D-GPEi工程菌发酵工艺条件。方法控制相关发酵参数,观察溶解氧浓度、比生长速率和培养时间对工程菌生长和质粒浓度的影响。结果发酵培养对数生长期溶解氧浓度控制在30%~50%。补料前比生长速率为0.5~0.7/h,6 h开始补料,比生长速率下降,12 h后比生长速率为0.1~0.2/h。连续发酵3批工程菌,21 h后收集菌体,得到菌体平均产量为89.4 g/L(A=52.6),质粒平均产量为359.8 mg/L。3批工程菌浓度和质粒拷贝数差异无显著意义。结论此发酵工艺得到工程菌浓度和质粒拷贝数较高,重复性好,适用于大规模工业化生产。

Optimization of Fermentation Procedure for Recombinant E.coli Strain with D-GPEi Plasmid DNA

Objective To ptimize a fermentation procedure for recombinant E.coli strain with D-GPEi plasmid DNA. Methods Observe the influence of fermentation parameters including dissolved oxygen concentration,specific growth rate and culture time on the growth of recombinant E.coli strain and the concentration of plasmid. Results The optimal dissolved oxygen concentration for fermentation was 30%～50%.The fed batch was started 6 h after fermentation.The specific growth rate of recombinant E.coli strain was 0.5～0.7/h before fed batch then decreased significantly to 0.1～0.2/h 12 h after fermentation.The yield of bacteria 21 h after fermentation was 89.4 g/L(A =52.6),and that of plasmid was 359.8 mg/L.Three consecutive batches of recombinant E.coli strains were fermented by the procedure,and the results showed no significant difference in bacterial concentration or the copy numbers of plasmids. Conclusion By the developed fermentation procedure,high bacterial concentration and plasmid copy number were obtained.The procedure showed good reproducibility and was suitable for large-scale production.