School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China.
School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China.
Enzyme Microb Technol. 2024 Oct;180:110503. doi: 10.1016/j.enzmictec.2024.110503. Epub 2024 Aug 22.
The scarcity of cellulases with low β-glucosidase activity poses a significant technological challenge in precisely controlling the partial hydrolysis of lignocellulose to cellobiose, crucial for producing high-value chemicals such as starch, inositol, and NMN. Trichoderma reesei is a primary strain in cellulase production. Therefore, this study targeted the critical β-glucosidase gene, Trbgl1, resulting in over an 86 % reduction in β-glucosidase activity. However, cellulase production decreased by 19.2 % and 20.3 % with lactose or cellulose inducers, respectively. Notably, transcript levels of cellulase genes and overall yield remained unaffected with an inducer containing sophorose. This indicates that β-glucosidase BGL1 converts lactose or cellulose to sophorose through transglycosylation activity, inducing cellulase gene transcription. The resulting enzyme cocktail, comprising recombinant cellulase and cellobiose phosphorylase, was applied for corn stover hydrolysis, resulting in a 24.3 % increase in glucose-1-phosphate yield. These findings provide valuable insights into obtaining enzymes suitable for the high-value utilization of lignocellulose.
纤维素酶中低β-葡萄糖苷酶活性的缺乏在精确控制木质纤维素的部分水解为纤维二糖方面带来了重大的技术挑战，而纤维二糖对于生产淀粉、肌醇和 NMN 等有价值的化学品至关重要。里氏木霉是纤维素酶生产的主要菌株。因此，本研究针对关键的β-葡萄糖苷酶基因 Trbgl1，导致β-葡萄糖苷酶活性降低了 86%以上。然而，当使用乳糖或纤维素诱导剂时，纤维素酶的产量分别下降了 19.2%和 20.3%。值得注意的是，含有棉子糖的诱导剂对纤维素酶基因的转录水平和整体产量没有影响。这表明β-葡萄糖苷酶 BGL1 通过转糖苷活性将乳糖或纤维素转化为棉子糖，从而诱导纤维素酶基因的转录。所得的酶混合物，包括重组纤维素酶和纤维二糖磷酸化酶，应用于玉米秸秆水解，葡萄糖-1-磷酸的产量增加了 24.3%。这些发现为获得适合木质纤维素高值利用的酶提供了有价值的见解。
