重组Pichia pastori高密度培养和表达过程的溶氧调控

在重组人血清白蛋白（recombinant human serum albumin，rHSA）Pichia pastori表达系统中，研究了高密度培养时细胞生长、改变碳源和诱导表达时溶氧的变化和调控规律，溶氧与细胞生长和重组蛋白表达密切相关。发酵前期的细胞生长阶段，细胞需氧降低表明碳源甘油的消耗，根据溶氧水平适时流加碳源甘油；改变碳源前，应停止流加甘油碳源，并以溶氧指标判断甘油是否消耗完全；重组蛋白诱导时流加甲醇的速度应缓慢增大，并保持细胞一定的需氧水平。高密度培养时通过流加底物速度、搅拌转速、通气量和富氧培养来关联控制发酵液溶氧水平。

Oxygen Controls in High Density Fermentation of Recombinant Pichia pastori

The relationship between cell growth,carbon source changing and recombinant human serum albumin(rHSA) expression,with dissolved oxygen(DO) in Pichia pastori system,was investigated.It showed that DO plays an important role in cell growth and recombinant protein expression process.At the cell growth phase of fermentation,DO requirement decreasing indicated that carbon source was being consumed,suggesting that glycerol be fed based on DO.When changing glycerol with methanol for(expression,) glycerol should be consumed completely by stopping fed-batch according to DO.The fed-batch speed is increasing slowly while DO is maintaining a proper level.The research suggested that DO controls in high density fermentation is associated with fed-batch,stir speed(r/min),VVM(L/min) and oxygen enrichment cultivation.