【摘要】 采用含黑曲霉(Aspergillus niger)纤维二糖酶基因的重组毕赤酵母发酵生产纤维二糖酶,对重组酵母的基因表达调控及发酵性能进行了研究。摇瓶试验结果表明:产酶培养基中甘油和玉米浆粉的适宜浓度分别为2.0%和3.0%,培养基最适pH值为6.0。甲醇作为碳源和基因表达的诱导物,对重组毕赤酵母的发酵结果有重要影响。发酵过程中每24h加入体积分数为1.0%的甲醇、质量浓度为0.2%的甘油及质量浓度为0.3%的玉米浆粉,有利于重组毕赤酵母持续合成纤维二糖酶。摇瓶发酵8d,发酵液中纤维二糖酶活力可达到9.01 IU/mL。更多还原

【Abstract】 Cellobiase production was carried out by recombinant Pichia pastoris containing Aspergillus niger cellobiase gene,and the main fermentation parameters were optimized.The fermentation result in shaking flasks showed that the optimal concentrations of glycerol and corn steep powder were 2.0%(w/v) and 3.0%(w/v) respectively,and the optimal pH value was 6.0.Methanol as carbon source and inducer has obvious effect on cellobiase production by recombinant Pichia pastoris.The activity of cellobiase could reach 9.01 IU/mL after 8d fermentation by addition of 1.0%(v/v) methanol,0.2%(w/v) glycerol and 0.3%(w/v) corn steep powder every 24 hours.The result is valuable in improving the efficiency of cellulose hydrolysis by cellulase and promoting industrialization of ethanol production from cellulosic material.更多还原