Wine Research Centre, University of British Columbia, Vancouver, BC, Canada.
FEMS Yeast Res. 2012 Feb;12(1):48-60. doi: 10.1111/j.1567-1364.2011.00762.x. Epub 2011 Dec 8.
Saccharomyces cerevisiae (S. cerevisiae) encounters a multitude of stresses during industrial processes such as wine fermentation including ethanol toxicity. High levels of ethanol reduce the viability of yeast and may prevent completion of fermentation. The identification of ethanol-tolerant genes is important for creating stress-resistant industrial yeast, and S. cerevisiae genomic resources have been utilized for this purpose. We have employed a molecular barcoded yeast open reading frame (MoBY-ORF) high copy plasmid library to identify ethanol-tolerant genes in both the S. cerevisiae S288C laboratory and M2 wine strains. We find that increased dosage of either RCN1 or RSA3 improves tolerance of S288C and M2 to toxic levels of ethanol. RCN1 is a regulator of calcineurin, whereas RSA3 has a role in ribosome maturation. Additional fitness advantages conferred upon overproduction of RCN1 and RSA3 include increased resistance to cell wall degradation, heat, osmotic and oxidative stress. We find that the M2 wine yeast strain is generally more tolerant of stress than S288C with the exception of translation inhibition, which affects M2 growth more severely than S288C. We conclude that regulation of ribosome biogenesis and ultimately translation is a critical factor for S. cerevisiae survival during industrial-related environmental stress.
酿酒酵母（Saccharomyces cerevisiae）在工业过程中会遇到多种压力，包括乙醇毒性。高浓度的乙醇会降低酵母的存活率，并可能阻止发酵完成。鉴定耐乙醇基因对于创造抗应激工业酵母非常重要，并且已经利用酿酒酵母基因组资源来实现这一目标。我们使用了一种分子条形码酵母开放阅读框（MoBY-ORF）高拷贝质粒文库，以鉴定酿酒酵母 S288C 实验室和 M2 葡萄酒菌株中的耐乙醇基因。我们发现，增加 RCN1 或 RSA3 的剂量均可提高 S288C 和 M2 对有毒水平乙醇的耐受性。RCN1 是钙调神经磷酸酶的调节剂，而 RSA3 在核糖体成熟中起作用。过量表达 RCN1 和 RSA3 带来的其他适应性优势包括增强对细胞壁降解、热、渗透和氧化应激的抗性。我们发现，与 S288C 相比，葡萄酒酵母 M2 菌株通常对压力更具耐受性，除了翻译抑制，这对 M2 的生长影响比对 S288C 的影响更严重。我们得出结论，核糖体生物发生的调节，最终是翻译，是酿酒酵母在工业相关环境压力下生存的关键因素。
