中文摘要：

嗜热毛壳菌Chaetomiumthermophilum CT2可产生具有重要工业生产价值的纤维素酶类.RT-PCR扩增cbh1成熟蛋白的编码基因,利用基因重组的方法构建可在毕赤酵母分泌表达系统中表达纤维二糖水解酶的重组表达载体,并转化毕赤酵母得到重组子.在毕赤酵母醇氧化酶AOX1基因启动子的作用下,重组蛋白得到高效表达,小规模发酵量达1.42mg/mL.表达蛋白分泌到培养基中,分子量约80kD;以脱脂棉为底物测得酶活为21U/mL.表达蛋白在60℃稳定,70℃保温60分钟仍保持90%的酶活力,具有较高的热稳定性.

英文摘要：

Chaetomium thermophilum CT2 produces extracellular cellulase with industrial value. PCR product consisting of the CBH I coding region without its signal sequences was cloned into the yeast secretive plasmid pPIC9K, which was then transformed into Pichia pastoris GS 115. Highly efficient production of the cellobiohydrolase Ⅰ were achieved in P pastoris under the control of the AOXI promoter, and the expressing level was 1.42mg/mL according to small-scale cultures. Recombinant cellobiohydrolase I had a molecular mass of 80 kDa, and the activity was up to 21U/mL.The recombinant enzyme was thermostable at 60℃ and remained 90% of its original activity after 60min at 70℃. The high level of fully active recombinant cellobiohydrolase I got from P pastoris makes this expression system attractive for fermentor and industrial applications.