里氏木霉Ex-26产纤维素酶发酵特征与转录组学研究OA

Trichoderma reesei possesses a strong capacity to synthesize and secrete a complete cellulase system.Through the determi-nation of key biochemical indicators during the fermentation cycle,coupled with transcriptome sequencing,this study analyzed the differ-ential gene expression profiles at the critical cellulase-producing stage(72 h)and the stage characterized by a marked decline in enzyme production efficiency(144 h).Results indicated that cellulase synthesis efficiency increased initially and then decreased.The efficiency at 144 h was significantly lower than that at 72 h.Concurrently,the fermentation broth viscosity increased,protein concentration decreased,and oxidative damage became more severe.Transcriptome analysis identified 2 773 differentially expressed genes(DEGs),comprising 1 554 downregulated and 1219 upregulated genes.The expression of cellulase-encoding genes and regulatory factor xyr1 decreased signifi-cantly.Further analysis revealed that the downregulated genes were primarily enriched in pathways related to cellulase synthesis,carbon metabolism,and protein synthesis.The upregulated genes were mostly associated with oxidative stress responses.This study elucidates the mechanism of the decreased cellulase synthesis efficiency in Trichoderma reesei Ex-26 during the later fermentation stage.The findings pro-vide a theoretical basis for optimizing fermentation processes and developing high-yield cellulase strains.