Single Mutation in Transcriptional Activator Xyr1 Enhances Cellulase and Xylanase Production in Trichoderma reesei on Glucose

Abstract

To achieve cost-effective production of lignocellulolytic enzymes for biorefinery processes, engineering transcription factors represents a powerful strategy to boost cellulase and xylanase in Trichoderma reesei. In this study, a novel mutation (R434L) in xylanase regulator 1 (Xyr1) was identified based on the yeast one-hybrid screening system. The point mutation was located in the middle homology region of Xyr1 with unclear functions, indicating a significant role for this domain in tuning Xyr1 transactivation. When constitutively expressed in T. reesei Δxyr1 (OEX R434L ), Xyr1 R434L led to highly improved production of both cellulases and xylanases on glucose compared with a strain similarly expressing Xyr1 (OEX). The respective 0.8-and 0.7-fold increases in extracellular pNPCase and xylanolytic activity were further verified to result from the greatly elevated transcription of major cellulase and xylanase genes in OEX R434L . Moreover, the saccharification efficiency of corn stover with OEX R434L enzyme cocktails was enhanced by 21% compared with that of OEX.

Culture of Trichoderma sp. with biochar to produce high-activity cellulase in a laboratory

“…(Gao et al 2008;Singh et al 2021b). Many studies have been conducted on genetic engineering (Xue et al 2016;Luo et al 2020;Chen et al 2020;Pant et al 2022) and artificial mutation (Dong et al 2019;Singh et al 2020;Dong et al 2022;Lv et al 2023) to produce improved cellulase from microbes. Additionally, there are various other strategies for culture technologies.…”