甘薯膨胀素在毕赤酵母中的表达及在纤维素酶解中的协同作用

The expression in Pichia pastoris and synergistic effect on cellulose degradation of Ipomoea batatas expansin

本研究构建了真核表达载体并表达具生物学活性的甘薯膨胀素.根据Genebank上甘薯膨胀素基因序列(No.DQ515800.1)设计引物,从甘薯cDNA中扩增出了IbEXP基因,并构建表达载体pGAP-IbEXP转化毕赤酵母.以酸处理后的玉米秸秆为纤维素底物,使用该菌株的发酵液,可以促进纤维素酶对纤维素的酶解,使葡萄糖的产量提高24%～54%.

This study intended to construct the eukaryotic expression vector and express the Ipomoea batatas expansin protein. Using the specific primers derived from the sequence of Ipomoea batatas expansin （No. DQ515800.1）, the IbEXP gene was cloned from Ipornoea batatas cDNA. The gene was subcloned and sequenced, and a recombinant plasmid pGAP-IbEXP was constructed by inserting IbEXP gene into pGAPZαA vector. Linearized pGAP-IbEXP was transformed into Pichia pastoris GS115 with the method of electroporation, and the IbEXP gene was integrated into the P. pastoris genome through homologous recombination. The excepted protein was obtained after fermentation. The fermentation broth of the strain showed a significant synergistic activity in corn stover hydrolysis when it was incuba- ted with cellulases. The glucose production was improved by 24%-54%.