Wine lees are the sediment that forms at the bottom of fermentation tanks or barrels and represent the second major winery by-product, accounting for about 25% of the total. They consist mainly of dead and living yeast cells containing proteins and peptides, polysaccharides, lipids and polyphenols, and their composition depends on numerous parameters including the yeast species and strains used and the grape cultivars. This makes lees a promising but highly variable raw material for valorization within the circular economy framework.
Grapevine trunk diseases (GTDs), and Petri disease in particular, are among the most severe problems facing viticulture. Two fungi, Phaeomoniella chlamydospora and Phaeoacremonium minimum , colonize the wood tissue of young grapevines, causing wood discoloration, necrosis, tiger-striped leaves, stunted growth, wilting and even plant death. With chemical options effectively removed by the ban on sodium arsenite, biocontrol strategies have become an attractive alternative.
To link the two problems, a team designed an integrated bioprocess built from a defined sequence of unit operations: fermentation design using Saccharomyces monocultures and sequential inoculations with non- Saccharomyces strains, ultrasound-assisted autolysis, enzymatic hydrolysis, and 3 kDa ultrafiltration. The resulting products were then tested in vitro and in vivo against both pathogens.
The results drew a sharp line between the product streams. High-molecular-weight autolysates showed no inhibition, whereas the post-hydrolysis fractions reduced mycelial growth of Phaeoacremonium minimum by 45%–75% and Phaeomoniella chlamydospora by 40–57% and decreased conidiation by up to 92% and 61%, respectively. They also reduced symptoms of wood discoloration by 47%–52% and 35%–73%, and endophytic fungal growth by 63%–84% and 80%–91%, respectively, indicating an association between hydrolysis and the appearance of antifungal activity. Untargeted metabolomics using UHPLC–ESI–TIMS–QTOF highlighted strain- and fermentation-dependent secondary metabolite signatures, with 448 features differentiating across fermentation conditions, and activity-based correlation fingerprinting identified 49 putative biomarkers negatively associated with pathogen growth. The authors conclude that fermentation design functions as a controllable upstream quality parameter, offering a scalable circular economy pathway for producing antifungal bioproducts from winery waste.
The work entitled “ Yeast-derived biomolecule mixtures from wine lees display antimicrobial activity: an integrated bioprocess approach against grapevine pathogens” was published in Systems Microbiology and Biomanufacturing (published on Aug. 12, 2026).
Systems Microbiology and Biomanufacturing
Experimental study
Not applicable
Yeast-derived biomolecule mixtures from wine lees display antimicrobial activity: an integrated bioprocess approach against grapevine pathogens
12-Aug-2026