Construction of enhanced transcriptional activators for improving cellulase production in Trichoderma reesei RUT C30

Enhancing cellulase production in Trichoderma reesei is of great interest for an economical biorefinery. Artificial transcription factors are a potentially powerful molecular strategy for improving cellulase production in T. reesei. In this study, enhanced transcriptional activators XYR1VP, ACE2VP, and ACE1VP were constructed by linking the C terminus of XYR1, ACE2, or ACE1 with an activation domain of herpes simplex virus protein VP16. T. reesei transformants T(XYR1VP), T(ACE2VP), and T(ACE1VP) showed improved cellulase and/or xylanase production. T(XYR1VP) has a cellulase-free phenotype but with significantly elevated xylanase production. Xylanase I and xylanase II activities [U/(mg biomass)] increased by 51% and 80%, respectively, in T(XYR1VP) in comparison with parental strain RUT C30. The filter paper activity of T(ACE2VP) in the Avicel-based medium increased by 52% compared to that of RUT C30. In the Avicel-based medium, T(ACE1VP) manifested an 80% increase in FPase activity and a 50% increase in xylanase activity as compared to those of RUT C30. Additionally, when pretreated corn stover was hydrolyzed, crude enzymes produced from T(ACE1VP) yielded a greater glucose release than did the enzymes produced by parental strain RUT C30. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40643-018-0226-4) contains supplementary material, which is available to authorized users.