毕赤酵母产α-葡聚糖酶发酵工艺研究

Study on fermentation technology of dextranase from Pichia pastoris

对毕赤酵母液体发酵产α-葡聚糖酶的主要影响因子进行了研究，考察了影响外源蛋白表达的因素，包括碳氮源、pH、装液量、接种量、温度等，单因素实验结果表明最佳培养及发酵条件为：最佳碳源氮源分别为甘油和YNB，甲醇诱导浓度为1．5％，pH为5．5～6．0，装液量为25mL／250mL，接种量为10％，表面活性剂为0．2％，摇床转速为200r／min。菌株的产酶水平由原来的47．50U／mL提高到73．16U／mL，酶活力提高了约1．5倍。

The main influencing factors of a - dextranase produced by Pichia pastoris were studied. Including the sources of carbon and nitrogen, pH, liquid volume, vaccinal volume, temperature, etc. The single - factor experiment results showed that the optimum conditions of culture and fermentation were： the best carbon and nitrogen source are respectively glycerol and YNB, methanol concentration of methanol 1.5 %, pH 5.5 - 6.0, liquid volume 25 mL/250 mL, vaccinal volume 10%, surfactant 0.2%, shaker rotate speed 200 r/min. The enzyme activity of strain increased from the original 47.50 U/mL to 73.16 U/mL, about 1.5 times.