초록
<P><B>Abstract</B></P><P><I>Trichoderma reesei</I> is a well-known cellulase producer and widely applied in enzyme industry. To increase its ability to efficiently decompose cellulose, the beta-glucosidase activity of its enzyme cocktail needs to be enhanced. In this study, a beta-glucosidase I coding sequence from <I>Penicillium decumbens</I> was ligated with the cellobiohydrolase I (<I>cbh1</I>) promoter of <I>T. reesei</I> and introduced into the genome of <I>T. reesei</I> strain Rut-C30 by <I>Agrobacterium</I>-mediated transformation. In comparison to that from the parent strain, the beta-glucosidase activity of the enzyme complexes from two selected transformants increased 6- to 8-fold and their filter paper activity (FPAs) was enhanced by 30% on average. The transformant's saccharifying ability towards pretreated cornstalk was also significantly enhanced. To further confirm the effect of heterologous beta-glucosidase on the cellulase activity of <I>T. reesei</I>, the heterologously expressed pBGL1 was purified and added to the enzyme complex produced by <I>T. reesei</I> Rut-C30. Supplementation of the Rut-C30 enzyme complex with pBGL1 brought about 80% increase of glucose yield during the saccharification of pretreated cornstalk. Our results indicated that the heterologous expression of a beta-glucosidase gene in <I>T. reesei</I> might produce balanced cellulase preparation.</P>