Membrane Lipid Remodeling in Non-Saccharomyces Wine Yeasts Under Ethanol Stress: From Mechanism Toward a Predictive Lipid Signature

Non-Saccharomyces yeasts shape the aroma, freshness, and reduced-alcohol profiles of wines, yet their oenological contribution is curtailed by a poor tolerance to ethanol. Because ethanol acts on the plasma membrane, the cell’s selective barrier, this limitation is rooted in the membrane lipidome, whose remodeling has been documented but never integrated into a wine-specific, predictive framework. This review provides that synthesis, keeping the non-Saccharomyces wine yeasts as the subject and Saccharomyces cerevisiae as a reference frame. It first describes how ethanol perturbs the bilayer and how the cell compensates through unsaturated fatty acids, ergosterol, phospholipid-class balance, and membrane fluidity. It then traces the concentration- and time-dependent remodeling of the lipidome, together with the medium-chain fatty-acid, temperature, and oxygen co-stressors accompanying it, and the comparative membrane biology distinguishing these yeasts from S. cerevisiae, including the markedly reduced uptake of exogenous sterols under oxygen limitation. Finally, it weighs the nutritional, process, and non-genetically modified strain-improvement strategies that reinforce them. The same lipid descriptors recur throughout, yet are seldom measured in improved wine strains. We argue that the membrane lipidome can be read as a candidate multivariate predictive signature of ethanol tolerance and of fermentation performance, and outline the validation it still requires.