Mejía-Barajas Jorge, Montoya-Pérez Rocío, Manzo-Avalos Salvador, Cortés-Rojo Christian, Riveros-Rosas Héctor, Cervantes Carlos, Saavedra-Molina Alfredo
Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán 58030, México.
Departamento de Bioquímica, Facultad de Medicina, UNAM, Ciudad de México 04510, México.
FEMS Microbiol Lett. 2018 Apr 1;365(7). doi: 10.1093/femsle/fny043.
Membrane fatty acid composition has an important role in yeast stress resistance, particularly in temperature tolerance. Most studies investigating temperature and membrane fatty acids use the yeast Saccharomyces cerevisiae without considering other yeasts, such as Kluyveromyces marxianus, which has physiological differences and industrial advantages with respect to S. cerevisiae. One of the primary traits of K. marxianus is its thermotolerance. The effect of fatty acid addition (oleic acid, linoleic acid, linolenic acid and araquidic acid) on the thermotolerance of the K. marxianus strain SLP1 was evaluated. SLP1 yeast exhibited temperature tolerance of up to 50°C; at 55°C, viability was reduced significantly, probably due to an increase in the generation of reactive oxygen chemical species. Externally added fatty acids were incorporated in the yeast membrane, increasing their proportion to approximately 70%, thereby changing membrane fluidity. SLP1 cells supplemented with polyunsaturated fatty acids decreased cell thermotolerance and increased the degree of lipoperoxidation, while arachidic acid addition exhibited a tendency to increase yeast thermotolerance.
膜脂肪酸组成在酵母抗逆性中起着重要作用，尤其是在耐温性方面。大多数研究温度与膜脂肪酸关系的实验都使用酿酒酵母，而未考虑其他酵母，如马克斯克鲁维酵母，它与酿酒酵母相比具有生理差异和工业优势。马克斯克鲁维酵母的主要特性之一是其耐热性。评估了添加脂肪酸（油酸、亚油酸、亚麻酸和花生酸）对马克斯克鲁维酵母菌株SLP1耐热性的影响。SLP1酵母表现出高达50°C的耐温性；在55°C时，存活率显著降低，这可能是由于活性氧化学物质生成增加所致。外部添加的脂肪酸被整合到酵母膜中，使其比例增加到约70%，从而改变了膜流动性。添加多不饱和脂肪酸的SLP1细胞降低了细胞耐热性并增加了脂质过氧化程度，而添加花生酸则表现出提高酵母耐热性的趋势。
