Aerobic fermentation was previously proposed to reduce the ethanol content of wine. The main constraint found for Saccharomyces cerevisiae to be used under these conditions was the high levels of acetic acid produced by all S. cerevisiae strains previously tested. This work addressed the identification of S. cerevisiae wine yeast strains suitable for aerobic fermentation and the optimization of fermentation conditions to obtain a reduced ethanol yield with acceptable volatile acidity. This approach unveiled a great diversity in acetic acid yield for different S. cerevisiae strains under aerobic conditions, with some strains showing very low volatile acidity. Three strains were selected for further characterization in bioreactors, with natural grape must, under aerobic and anaerobic conditions. Ethanol yields were lower under aerobic than under anaerobic conditions for all strains, and acetic acid levels were low for two of them. Strain-dependent changes in volatile compounds were also observed between aerobic and anaerobic conditions. Finally, the process was optimized at laboratory scale for one strain. This is the first report of S. cerevisiae wine strains showing low acetic acid production under aerobic conditions and paves the way for simplified aerobic fermentation protocols aimed to reducing the alcohol content of wines.

以前曾提出需氧发酵来降低葡萄酒的乙醇含量。发现在这些条件下使用酿酒酵母的主要限制是先前测试的所有酿酒酵母菌株产生的乙酸水平高。此工作中处理的识别酿酒酵母酿酒酵母菌株适于好氧发酵和发酵条件的优化，以获得具有可接受的挥发性酸度降低乙醇产量。这种方法揭示了不同酿酒酵母的乙酸产量的巨大差异有氧条件下的菌株，一些菌株表现出非常低的挥发性酸度。选择了三个菌株在生物反应器中进一步表征，在有氧和厌氧条件下使用天然葡萄汁。所有菌株在需氧条件下的乙醇产量都低于在厌氧条件下的产量，其中两个菌株的乙酸水平较低。在有氧和无氧条件之间也观察到挥发性化合物的应变依赖性变化。最后，该过程在实验室规模上针对一种菌株进行了优化。这是第一份关于在有氧条件下显示低乙酸产量的酿酒酵母菌株的报告，并为旨在降低葡萄酒酒精含量的简化有氧发酵方案铺平了道路。