Limiting magnesium availability: a novel approach to managing brettanomyces spoilage in winemaking
Brettanomyces is a world-renowned yeast that negatively impacts the chemical composition of wines through the production of metabolites that negatively impact the sensory properties of the final product. Its resilience in wine conditions and ability to produce off-flavors make it a challenge for winemakers. Currently, the primary control technique involves adding sulfur dioxide (SO2); however, some Brettanomyces strains are developing resistance to this preservative agent.  Therefore, new management strategies are necessary to control this spoilage yeast.
Mineral nutrients could be a promising approach to control Brettanomyces growth in winemaking. Magnesium (Mg2+), is specifically recognized as a protective element against yeast stress and can prevent cellular death from temperature shock and ethanol.  In this study, the effect of mineral concentration on Brettanomyces metabolism under winemaking conditions was investigated. Brettanomyces sensitivity to Mg2+ limitation was assessed by culturing it in the presence of decreasing Mg2+ concentrations. While 1 mg/L of Mg2+ supported normal growth, concentrations below 0.5 mg/L significantly limited growth, and 0.1 mg/L was unable to support proliferation. Long-term Mg2+ deficiency resulted in permanent viability reduction.
This nutritional study identifies Mg2+ as essential for Brettanomyces metabolism and provides a starting point for designing experiments to manage Brettanomyces spoilage in wine, improving quality and stability. Understanding the physiology and nutritional requirements of Brettanomyces can lead to more informed decisions and innovative strategies for managing spoilage, resulting in better wine quality, consumer satisfaction, and higher profits for the wine industry. The study assists in finding alternatives to SO2 to produce fault-free wines that align with current wine consumer preferences.
The ARC Training Centre for Innovative Wine Production
The Australian Wine Research Institute
Pernod Ricard Winemakers
1) Bartel, C., et al. (2021). “Adaptive evolution of sulfite tolerance in Brettanomyces bruxellensis.” FEMS Yeast Research 21(5), https://doi.org/10.1093/femsyr/foab036.
2) Birch, R. M. and G. M. Walker (2000). “Influence of magnesium ions on heat shock and ethanol stress responses of Saccharomyces cerevisiae.” Enzyme and Microbial Technology 26(9-10): 678-687, https://doi.org/10.1016/S0141-0229(00)00159-9.
Issue: ICGWS 2023
1 Wine Science Discipline, School of Agriculture Food and Wine, Waite Research Institute, The University of Adelaide, Urrbrae, South Australia 5064, Australia
2 Australian Research Council Training Centre for Innovative Wine Production, The University of Adelaide, Urrbrae, South Australia 5064, Australia
3 Pernod Ricard Winemakers, 1914 Barossa Valley Way, Rowland Flat, SA 5352, Australia
4 The Australian Wine Research Institute, PO Box 197, Glen Osmond, Adelaide, SA 5064, Australia
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Brettanomyces, wine spoilage, sulfur dioxide, mineral nutrients, magnesium, wine quality