中文摘要：

通过NCBI（美国国立生物技术信息中心）对黑曲霉的来源外切葡聚糖酶基因（cbh1）的氨基酸序列进行分析，发现其16个活性部位中有6个位点附近的氨基酸为毕赤酵母（Pichiapastoris）表达的稀有密码子。利用反向长距离PCR技术将这些活性位点附近的稀有密码子定点突变为毕赤酵母表达偏爱密码子。将优化后的表达载体pPICZctA—cbhlm转入毕赤酵母KM71H菌株中进行诱导表达。经密码子优化后的cbhlm基因较未优化前cbhl基因的表达量提高了17％。

英文摘要：

NCBI analysis revealed that there were sixteen active sites in cellobiohydrolase gene （cbhl） from Aspregillus niger, and were found rare codons around six active sites. To improve expression efficiency of recombinant cellobio- hydrolase in Pichia pastoris KM71 H, those rare codons around active site of cbhl were replaced with preferable codons used in P. pastoris by long-distance inverse PCR. The recombinant plasmid pPICZαA -cbhlm which contained the mod- ified cbhl sequence was transformed in P. pastoris KM71H. After methanol induction, the expression level of cbhl m was 17 % higher than that of cbhl.