How Wine Yeasts Help Detoxify Copper and Pesticides
Insights from the University of Montpellier
Source: OENO One – University of Montpellier Study (2024)
A new study from the University of Montpellier sheds light on how different wine yeast species react to copper and pesticide residues in grape must — and how effectively they can detoxify these substances during fermentation. The findings offer promising implications for organic and sustainable viticulture.
🧫 What the Researchers Found
The Montpellier team tested several yeast strains commonly used in winemaking, including Saccharomyces cerevisiaeand non-Saccharomyces species such as Metschnikowia pulcherrima, Starmerella bacillaris, and Torulaspora delbrueckii.
Copper: At typical vineyard concentrations, copper showed little to no inhibitory effect on most yeasts. Within just 48 hours, many strains could remove copper ions from the must, likely through adsorption to cell walls or internal binding mechanisms.
Pesticides: Residual pesticides, on the other hand, slowed fermentation significantly, especially among non-Saccharomyces species. Detoxification was observed but much less efficient than copper removal.
Different Mechanisms: The results indicate that copper and pesticide detoxification occur through separate biochemical pathways. A strain that binds copper effectively does not necessarily perform well at degrading pesticide residues.
⚙️ The Science Behind It
The research builds on growing evidence that yeasts have evolved adaptive mechanisms to cope with copper, a metal widely used as a fungicide in vineyards. In S. cerevisiae, for instance, resistance is linked to multiple copies of the CUP1 gene, which encodes a copper-binding protein. While this adaptation helps the yeast survive, it can also lead to increased hydrogen sulfide (H₂S) production, affecting wine aroma and quality.
Studies from the same research group and others show that copper exposure can alter yeast metabolism — influencing acetaldehyde levels, sulfur dioxide (SO₂) dynamics, and fermentation kinetics. Meanwhile, pesticide degradation appears to depend on species-specific enzymatic pathways, some of which remain poorly understood.
🌱 Implications for Organic and Sustainable Winemaking
For winemakers aiming to reduce chemical inputs, these findings are significant. By strategically selecting yeast strainsbased on their detoxification abilities, producers can:
Lower the chemical burden in grape must
Improve fermentation performance under residue stress
Enhance wine quality and environmental sustainability
The study’s authors emphasize that future research will focus on the physiological and genetic mechanisms behind yeast detoxification. This could eventually lead to the development of customized yeast strains optimized for low-input or organic winemaking systems.
Read the full research article:
👉 “Copper and pesticide degradation by wine yeasts during alcoholic fermentation” — OENO One (2024)
