Profiling and evaluating wine lees by-products from various yeast strains against grapevine pathogens

Abstract

Wine lees are the sediment that settles at the bottom of wine barrels, tanks, or bottles during the winemaking process and represent the second most significant by-product of wineries. Wine lees consist primarily of dead yeast cells which contain a complex mixture of both organic and inorganic molecules, such as proteins, peptides, polysaccharides, sterols, and long-chain fatty acids. This study aimed to evaluate the potential role of wine lees in combating grapevine pathogens. Six different wine yeast species were tested in fifteen fermentation schemes under monoculture and mixed-culture conditions. Fermentations were conducted in a laboratory medium that mimicked wine conditions (grape juice medium). The fermentation rate was monitored daily using an enzymatic method (Glucose/Fructose) following the OIV official protocol along with CO₂ emission measurements. Following fermentation, yeast biomass was autolyzed and digested to produce High Molecular Weight Biomolecule Mixtures (HMW-BM) and Low Molecular Weight Biomolecule Mixtures (LMW-BM). These biomolecule mixtures were then evaluated in vitro for their ability to inhibit the growth of Botrytis cinerea, Aspergillus carbonarius, Phaeomoniella chlamydospora, and Phaeoacremonium minimum. Our results indicate that the most effective biomolecule mixture with a protective mode of action against grapevine pathogens was LMW-BM.

Aknowledgements

The research project entitled «reLees» is implemented in the framework of H.F.R.I call “Basic research Financing (Horizontal support of all Sciences)” under the National Recovery and Resilience Plan “Greece 2.0” funded by the European Union – NextGenerationEU (H.F.R.I. Project Number:15100).

References

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