Comparative transcriptome analysis of Trichoderma reesei reveals different gene regulatory networks induced by synthetic mixtures of glucose and β-disaccharide

Abstract

The mixture of glucose and β-disaccharide (MGD) synthesized by transglycosylation of glucose as a low-cost soluble carbon source can efficiently induce cellulase production in Trichoderma reesei, which holds potential for the biorefining of lignocellulosic biomass. However, it is not yet fully understood how MGD induces T. reesei cellulase. In this study, transcriptomic analyses were conducted to investigate the molecular basis of MGD for lignocellulose-degrading enzyme production of T. reesei Rut C30 compared with that on lactose. Particular attention was paid to CAZymes, transcription factors, transporters and other protein processing pathways related to lignocellulose degradation. As a result, MGD can elicit transcription of GH5-, GH6- and GH7-encoding cellulases that is up to 1.4-fold higher than that induced by lactose, but GH11- and GH74-encoding xylanases are downregulated by 1.7- and 4.4-fold, respectively. Gene expression profiles suggest that the transcription activators xyr1 and vib1 are significantly upregulated and that the mitogen-activated protein kinase pathway is strengthened compared to the case of lactose induction. In addition, hac1-encoding UPR-specific transcription factors are significantly upregulated by MGD, which may be enhanced due to proper folding and processing of nascent proteins. These findings provide a theoretical basis for further understanding the characterization of efficient cellulase production using MGD as an inducer in T. reesei and offer potential strategies for strain improvement.

Induction of cellulase production in Trichoderma reesei by a glucose–sophorose mixture as an inducer prepared using stevioside

“…At present, lactose is one of the most widely used soluble cellulase inducers. 12,13 However, in China, due to the higher cost of lactose than other soluble inducers, lactose has not been applied in the industrial production of cellulase. The xylanase activity of MGS was 27.68-and 7.66-fold higher than those of glucose and cellobiose, respectively (p < 0.01).…”

“…However, lactose is not suitable for the industrial production of cellulase due to its low productivity and high cost in China. 5,12,13 On the other hand, the induction effect of sophorose is 2500 times higher than that of cellobiose, 14,15 which is the most efficient cellulase inducer of T. reesei identied thus far. However, natural sophorose is relatively rare, so its cost remains high.…”

Induction of cellulase production by Sr2+ in Trichoderma reesei via calcium signaling transduction

“…The economic and practical degradation of cellulose has been widely recognized and accepted (Li et al 2018 ). Cellulose degradation is dependent on Trichoderma reesei , a strain that efficiently produces cellulase and hemicellulase (Fischer et al 2021 ; Li et al 2016 , 2021 ; Martzy et al 2021 ; Yan et al 2021 ). Trichoderma reesei can produce large amounts of cellulases and hemicellulases using inducible carbon sources (such as Avicel).…”