Centro de Estudios en Ciencia y Tecnología de Alimentos (CECTA), Universidad de Santiago de Chile (USACH), Santiago, Chile.
Departamento de Ciencia y Tecnología de los Alimentos, Universidad de Santiago de Chile (USACH), Santiago, Chile.
Biol Res. 2023 Jul 29;56(1):43. doi: 10.1186/s40659-023-00453-2.
For more than 20 years, Saccharomyces cerevisiae has served as a model organism for genetic studies and molecular biology, as well as a platform for biotechnology (e.g., wine production). One of the important ecological niches of this yeast that has been extensively studied is wine fermentation, a complex microbiological process in which S. cerevisiae faces various stresses such as limited availability of nitrogen. Nitrogen deficiencies in grape juice impair fermentation rate and yeast biomass production, leading to sluggish or stuck fermentations, resulting in considerable economic losses for the wine industry. In the present work, we took advantage of the "1002 Yeast Genomes Project" population, the most complete catalogue of the genetic variation in the species and a powerful resource for genotype-phenotype correlations, to study the adaptation to nitrogen limitation in wild and domesticated yeast strains in the context of wine fermentation. We found that wild and domesticated yeast strains have different adaptations to nitrogen limitation, corroborating their different evolutionary trajectories. Using a combination of state-of-the-art bioinformatic (GWAS) and molecular biology (CRISPR-Cas9) methodologies, we validated that PNP1, RRT5 and PDR12 are implicated in wine fermentation, where RRT5 and PDR12 are also involved in yeast adaptation to nitrogen limitation. In addition, we validated SNPs in these genes leading to differences in fermentative capacities and adaptation to nitrogen limitation. Altogether, the mapped genetic variants have potential applications for the genetic improvement of industrial yeast strains.
二十多年来,酿酒酵母一直是遗传研究和分子生物学的模式生物,也是生物技术(如葡萄酒生产)的平台。这种酵母广泛研究的一个重要生态位是葡萄酒发酵,这是一个复杂的微生物过程,酿酒酵母在这个过程中面临着各种压力,如氮的有限可用性。葡萄汁中的氮缺乏会降低发酵速度和酵母生物量的产生,导致发酵缓慢或停滞,给葡萄酒行业造成巨大的经济损失。在本工作中,我们利用“1002 酵母基因组计划”群体,该群体是该物种遗传变异的最完整目录,也是基因型-表型相关性的强大资源,研究了在葡萄酒发酵背景下野生和驯化酵母菌株对氮限制的适应。我们发现野生和驯化酵母菌株对氮限制有不同的适应,证实了它们不同的进化轨迹。我们使用最先进的生物信息学(GWAS)和分子生物学(CRISPR-Cas9)方法相结合,验证了 PNP1、RRT5 和 PDR12 与葡萄酒发酵有关,其中 RRT5 和 PDR12 也参与了酵母对氮限制的适应。此外,我们验证了这些基因中的 SNP 导致发酵能力和氮限制适应的差异。总之,映射的遗传变异有可能应用于工业酵母菌株的遗传改良。