Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Enzyme Microb Technol. 2011 Sep 10;49(4):366-71. doi: 10.1016/j.enzmictec.2011.06.013. Epub 2011 Jun 24.
Trichoderma reesei 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 Penicillium decumbens was ligated with the cellobiohydrolase I (cbh1) promoter of T. reesei and introduced into the genome of T. reesei strain Rut-C30 by Agrobacterium-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 T. reesei, the heterologously expressed pBGL1 was purified and added to the enzyme complex produced by T. reesei 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 T. reesei might produce balanced cellulase preparation.
里氏木霉是一种著名的纤维素酶产生菌，广泛应用于酶工业。为了提高其高效分解纤维素的能力，需要增强其酶制剂中β-葡萄糖苷酶的活性。本研究将从软毛青霉中克隆的β-葡萄糖苷酶 I 编码序列与里氏木霉的纤维二糖水解酶 I（cbh1）启动子连接，并通过农杆菌介导转化将其导入里氏木霉 Rut-C30 菌株的基因组中。与亲本菌株相比，两个选定的转化体的酶复合物中的β-葡萄糖苷酶活性提高了 6-8 倍，其滤纸活性（FPAs）平均提高了 30%。转化体对预处理玉米秸秆的糖化能力也显著增强。为了进一步证实异源β-葡萄糖苷酶对里氏木霉纤维素酶活性的影响，纯化了异源表达的 pBGL1 并添加到里氏木霉 Rut-C30 产生的酶复合物中。在预处理玉米秸秆的糖化过程中，向 Rut-C30 酶复合物中添加 pBGL1 可使葡萄糖产率提高 80%。我们的结果表明，在里氏木霉中异源表达β-葡萄糖苷酶基因可能会产生平衡的纤维素酶制剂。
