Abstract: Expression of porcine interferon-a (pIFN-a) under high density recombinant Pichia pastoris cultivation was conducted in a 5 L batch-scaled bioreactor. The results indicated that a high and stable oxygen uptake rate (OUR) during induction phase was the most important factor in achievement of effective pIFN-a production. On-line measurements of multi-variables would help to interpret the reasons for the formation of high and stable OUR. The high and stable OUR [200~280 mmol/(L×h)] could be realized by adjusting specific growth rate with a proper substrate feeding strategy during transient phase, followed by controlling methanol concentration at a moderate level (around 10 g/L) during the induction phase. Under high and stable OUR condition, the highest pIFN-a antiviral activity reached 6.6×106 IU/mL, which was about 10~300 folds of those obtained under lower OUR in the same bioreactor and the shaking flask experiments.

Key words: Pichia pastoris, expression, fed-batch culture, oxygen uptake rate, porcine interferon-a

摘要： 在5 L发酵罐中进行了重组毕赤酵母高密度培养表达猪a干扰素(IFN-a)的研究. 在诱导阶段，高且稳定的摄氧速度(OUR)是实现毕赤酵母流加培养高效表达IFN-a的最关键因素，利用多变量在线测量可有效地帮助寻找高且稳定的OUR的形成条件. 结果表明，高且稳定的OUR[约200~280 mmol/(L×h)]可通过适度控制混加期及诱导期的菌体比增殖速度和甲醇浓度(约10 g/L)而得以实现. 在此条件下，猪a干扰素最高活性可达6.6×106 IU/mL，是较低OUR的罐发酵及摇瓶条件下的10~300倍.

关键词: 毕赤酵母, 表达, 流加培养, 摄氧速率, 猪a干扰素