毕赤酵母表达阿片肽发酵条件的研究

Study On Fermentation Conditions for Expression of Opioid Peptide by Pichia pastoris

研究了由毕赤酵母胞内两步发酵法表达活性小分子阿片肽的条件。正交实验确定最佳生长条件为:甘油24g/L、酵母膏11g/L、蛋白胨22g/L、YNB20ml/L,初始pH5.0。菌体密度可达2.46;以单因素实验确定最佳表达条件为:起始菌体浓度2.44,初始pH6.25,每10h流加0.6%甲醇(v/v),表达时间96h。阿片肽250ml摇瓶产量由196mg/L提高至496mg/L。

The two-step fermentation conditions of opioid peptide expressed in Pichia pastoris were studied. The growth medium optimized using orthogonal design was as follows： glycerol 24g/L, yeast extract 1 lg/L, peptone 22g/L, YNB 20ml/L and initial pH 5.0. As a result, the final optical density was 2.46. The expression conditions were optimized by singlefactor experiment： initial optical density 2.44 with initial pH 6.25, methanol concentration 0.6% （v/v） with the adding frequency of once per 10h, expressed for 96h. The productivity of opioid peptide was increased from 196mg/L to 496mg/L in 250ml flask.