Fermentation is a process in which sugars are transformed into a new product through chemical reactions carried out by microorganisms. Since ancient times, humans have taken advantage of the natural fermentation process to develop many products, including foods, medicines, and fuels. In this article, we provide a close look at the history of fermentation, demonstrating why this natural process is humans’ most ancient biotechnological tool. This article will help you to understand the different types of fermentation and the current uses of the fermentation process.

Thefilamentous fungus Trichoderma reesei is renowned for its exceptional ability to secrete cellulolytic enzymes, which play a crucial role in the hydrolysis of lignocellulose biomass. The expression of fungal cellulases is meticulously regulated at the transcriptional level, depending on the carbon source available in the medium. To obtain new insights into the transcriptional network controlling cellulase expression in T. reesei, we analyzed RNA-Seq data and identified and characterized a new transcription factor, Rme1, that regulates the expression of cellulolytic genes. Combining functional genomics and protein-DNA interaction assay, we showed that Rme1 acts as a repressor of cellulase production in T. reesei by directly regulating two critical genes involved in cellulose degradation: the cellobiohydrolase cel7a and the carbon catabolite repressor cre1. This is the first report of a transcription factor regulating Cre1. This study contributes to a better understanding of the complex regulation of the cellulolytic system of T. reesei and may be useful for the genetic modification of strains for the biorefinery industry.

The filamentous fungus Trichoderma reesei is a major industrial source of holocellulolytic enzymes, and its response to complex carbon sources is regulated by nutrient-sensing mechanisms, including the cyclic adenosine monophosphate (cAMP)–protein kinase A (PKA) signaling pathway. Here, we integrated transcriptomics, quantitative proteomics, and phosphoproteomics to analyze PKAc1-associated responses in the parental strain QM9414 and a Δ pkac1 strain cultivated under glucose or sugarcane bagasse conditions. Deletion of pkac1 was associated with altered growth-related phenotypes and reduced extracellular activities of selected biomass-depolymerizing enzymes. Multi-omics profiling revealed condition-dependent changes affecting subsets of carbohydrate-active enzymes (CAZymes) genes and proteins, nutrient transporters, stress-associated proteins, and regulatory factors. Phosphoproteomics identified phosphorylation-state changes associated with pkac1 deletion, including reduced phosphorylation at sites enriched for the PKA consensus motif. In silico peptide docking was used to prioritize candidate PKAc1-associated substrates for future validation, including a Sec 7-derived peptide with favorable docking behavior relative to the control peptide. Together, these data support a working model in which PKAc1 contributes to regulatory and phosphorylation-state remodeling during adaptation to sugarcane bagasse, with effects on the magnitude and/or timing of selected CAZyme-related outputs in T. reesei .