中文摘要：

以表达人Cu,Zn-SOD的重组毕赤酵母为出发菌株,通过摇瓶实验研究发酵初始pH值、诱导剂浓度、诱导温度和培养基组成等因素对目的蛋白表达水平的影响.实验结果表明,培养基组分对目的蛋白表达水平的影响最大.与YPG培养基相比,菌株在FM22培养基（含0.15％组氨酸及PTM4）中目的蛋白表达量提高5.5倍.在优化摇瓶发酵条件下（诱导剂浓度1％,诱导温度27℃,FM22培养基（含0.15％组氨酸及PTM4）,初始pH值为6.0）,发酵液上清酶活水平为895 U/mL,较初始提高8.5倍;以摇瓶实验结果指导5L罐发酵,得到13 539 U/mL酶活,为摇瓶试验的15倍.

英文摘要：

In this experiment,based on expression of human Cu,Zn-SOD recombinant Pichia yeast strain,we studied inducer concentration,medium composition and other factors how influence the expression of the purpose protein level in shake culture.Among these factors,different composition of medium is the major factor in all.Strains cultured in FM22 （include 0.15％ histidine and PTM4） have a huge increase about 5.5 times than YPG medium in expression of purpose protein level.The results are as follows：inducer concentration of 1％,induction temperature 27 ℃,FM22 medium （containing 0.15％ histidine and PTM4）,initial pH value 6.0.In this finally optimized condition,the level of activity in shake flask was 895 U/mL,increased by 8.5 times compared with the initial; shake flask experiments serves as a guide to fermentation of 5L tank,enzyme activity in 5 L fermentor reaches up to 13 539 U/mL,and is 15 times than the flask culture.