Sunyer-Figueres Mercè, Mas Albert, Beltran Gemma, Torija María-Jesús
Grup de Biotecnologia Enològica, Departament de Bioquímica i Biotecnologia, Facultat d'Enologia, Universitat Rovira i Virgili, C/Marcel·lí Domingo, 1, 43007 Tarragona, Catalunya, Spain.
Antioxidants (Basel). 2021 Oct 29;10(11):1735. doi: 10.3390/antiox10111735.
During alcoholic fermentation, is subjected to several stresses, among which ethanol is of capital importance. Melatonin, a bioactive molecule synthesized by yeast during alcoholic fermentation, has an antioxidant role and is proposed to contribute to counteracting fermentation-associated stresses. The aim of this study was to unravel the protective effect of melatonin on yeast cells subjected to ethanol stress. For that purpose, the effect of ethanol concentrations (6 to 12%) on a wine strain and a lab strain of was evaluated, monitoring the viability, growth capacity, mortality, and several indicators of oxidative stress over time, such as reactive oxygen species (ROS) accumulation, lipid peroxidation, and the activity of catalase and superoxide dismutase enzymes. In general, ethanol exposure reduced the cell growth of and increased mortality, ROS accumulation, lipid peroxidation and antioxidant enzyme activity. Melatonin supplementation softened the effect of ethanol, enhancing cell growth and decreasing oxidative damage by lowering ROS accumulation, lipid peroxidation, and antioxidant enzyme activities. However, the effects of melatonin were dependent on strain, melatonin concentration, and growth phase. The results of this study indicate that melatonin has a protective role against mild ethanol stress, mainly by reducing the oxidative stress triggered by this alcohol.
在酒精发酵过程中，酵母会受到多种压力，其中乙醇起着至关重要的作用。褪黑素是酵母在酒精发酵过程中合成的一种生物活性分子，具有抗氧化作用，被认为有助于对抗与发酵相关的压力。本研究的目的是揭示褪黑素对遭受乙醇胁迫的酵母细胞的保护作用。为此，评估了乙醇浓度（6%至12%）对一种葡萄酒酵母菌株和一种实验室酵母菌株的影响，随着时间的推移监测其活力、生长能力、死亡率以及氧化应激的几个指标，如活性氧（ROS）积累、脂质过氧化以及过氧化氢酶和超氧化物歧化酶的活性。总体而言，乙醇暴露降低了酵母的细胞生长并增加了死亡率、ROS积累、脂质过氧化和抗氧化酶活性。补充褪黑素减轻了乙醇的影响，通过降低ROS积累、脂质过氧化和抗氧化酶活性来促进细胞生长并减少氧化损伤。然而，褪黑素的效果取决于菌株、褪黑素浓度和生长阶段。本研究结果表明，褪黑素对轻度乙醇胁迫具有保护作用，主要是通过减少这种酒精引发的氧化应激来实现的。
