Metabolic and transcriptomic insights into a GalNAc/Man-Specific lectin in yeast fermentation

Abstract

Brewers yeast (Saccharomyces cerevisiae) plays a central role in fermentation, and improving its performance is crucial in the brewing industry. This study explored how Cyclina sinensis lectin (CSL), a bioactive peptide from shellfish, influences yeast metabolism using proteomics and metabolomics. CSL bound to yeast peptidoglycan in a concentration-dependent manner and altered cell surface structure. Proteomic analysis revealed 117 differentially expressed proteins after 24 h of CSL treatment, with upregulation of key glycolytic enzymes (e.g., hexokinase, GAPDH) and downregulation of TCA cycle enzymes, suggesting enhanced ethanol production via glycolysis activation and TCA suppression. Metabolomic profiling further confirmed this, showing increased -D-glucose, glucose-6-phosphate, NAD+, and glutathione, alongside reduced TCA intermediates like malic acid. These results indicate CSL promotes ethanol accumulation by reprogramming central carbon metabolism. This study provides novel insight into the metabolic modulation of yeast by marine lectins and suggests potential applications of CSL in improving fermentation