Salt-resistant yeast strains are highly demanded by industry due to the exposure of yeast cells to high concentrations of salt, in various industrial bioprocesses. The aim of this study was to perform a physiological and transcriptomic analysis of a salt-resistant Saccharomyces cerevisiae (S. cerevisiae) mutant generated by evolutionary engineering. NaCl-resistant S. cerevisiae strains were obtained by ethyl methanesulfonate (EMS) mutagenesis followed by successive batch cultivations in the presence of gradually increasing NaCl concentrations, up to 8.5% w/v of NaCl (1.45 M). The most probable number (MPN) method, high-performance liquid chromatography (HPLC), and glucose oxidase/peroxidase method were used for physiological analysis, while Agilent yeast DNA microarray systems were used for transcriptome analysis. NaCl-resistant mutant strain T8 was highly cross-resistant to LiCl and highly sensitive to AlCl3. In the absence of NaCl stress, T8 strain had significantly higher trehalose and glycogen levels compared to the reference strain. Global transcriptome analysis by means of DNA microarrays showed that the genes related to stress response, carbohydrate transport, glycogen and trehalose biosynthesis, as well as biofilm formation, were upregulated. According to gene set enrichment analysis, 548 genes were upregulated and 22 downregulated in T8 strain, compared to the reference strain. Among the 548 upregulated genes, the highest upregulation was observed for the FLO11 (MUC1) gene (92-fold that of the reference strain). Overall, evolutionary engineering by chemical mutagenesis and increasing NaCl concentrations is a promising approach in developing industrial strains for biotechnological applications.

中文翻译：

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通过进化工程获得的耐盐酿酒酵母突变体的生理学和转录组学分析。


由于在各种工业生物过程中酵母细胞暴露于高浓度的盐，工业界对耐盐酵母菌株的需求量很大。本研究的目的是对通过进化工程产生的耐盐酿酒酵母（S. cerevisiae）突变体进行生理和转录组分析。通过甲磺酸乙酯 (EMS) 诱变，然后在逐渐增加 NaCl 浓度（高达 8.5% w/v 的 NaCl (1.45 M)）的情况下连续分批培养，获得了耐 NaCl 酿酒酵母菌株。采用最可能数（MPN）法、高效液相色谱（HPLC）和葡萄糖氧化酶/过氧化物酶法进行生理分析，同时采用安捷伦酵母DNA微阵列系统进行转录组分析。耐NaCl突变株T8对LiCl具有高度交叉抗性，对AlCl高度敏感。在没有 NaCl 胁迫的情况下，与参考菌株相比，T8 菌株具有显着更高的海藻糖和糖原水平。通过DNA微阵列进行的全局转录组分析表明，与应激反应、碳水化合物运输、糖原和海藻糖生物合成以及生物膜形成相关的基因上调。根据基因集富集分析，与参考菌株相比，T8菌株中有548个基因上调，22个基因下调。在 548 个上调基因中，观察到 FLO11 (MUC1) 基因上调最高（是参考菌株的 92 倍）。总体而言，通过化学诱变和增加氯化钠浓度进行的进化工程是开发用于生物技术应用的工业菌株的一种有前途的方法。