中心复合实验设计法优化重组毕赤酵母表达猪胰岛素前体的培养基和诱导pH

Optimization of medium composition and inducing pH of porcine insulin precursor fermentation by recombinant Pichia pastoris using of central composite design

毕赤酵母中猪胰岛素前体(Porcine Insulin Precursor,PIP)的表达受到培养基组成及培养环境的影响。本文首先通过部分因子法设计实验,筛选出影响PIP表达的显著因子。实验结果表明,在试验范围内,甲醇补料量和硫酸铵浓度为正效应因子,诱导pH为负效应因子。在此基础上,经过快速登高法逼近显著因子的最优值后,再在此值附近利用中心复合法设计实验,最终得到了PIP表达的最佳条件。经过多批次实验验证,在此条件下PIP的表达量为120.4mg/L,比优化前的值41.5mg/L提高了将近两倍。

The production of porcine insulin precursor （PIP） by Pichia pastoris was markedly influenced by medium composition and culture environment. A partial factors design method was used to investigate the effects of medium composition and culture conditions. The results indicated that the feeding amount of methanol and concentration of （NIL）2SO4 were positive effectors and pH was a negative effector in the design. Then the optimal values of these key factors were approached by fast descend method. Finally, by central composite design, an optimal expression condition was obtained. The PIP concentration was increased from 41.5 mg/L to 120.4 mg/L under the optimal conditions, and the results were validated by repeated experiments under the optimized cultivation conditions.