Abstract A major challenge for the production of bio-ethanol is to develop yeast that can sustain growth under high temperature. Here, we show the application of an artificial protein quality control (APQC) system to an industrial Saccharomyces cerevisiae strain for improving thermo-tolerance, a key trait for a bio-ethanol fermentation program. All engineered strains exhibited a significantly higher growth rate and cell viability at 37 °C, which conferred increased thermo-tolerance and more efficient glucose conversion to ethanol. Furthermore, the analysis of ubiquitination and the enzyme activities of pyruvate kinase (PK) and malate dehydrogenase (MDH) indicated strengthened protein quality, implying that proteostasis had been effectively improved at higher temperature. Industrial material fermentation results from yeast-RSP5-UBC4 (combined expression of ubiquitin conjugated enzyme E2 and ubiquitin ligase E3) showed a 2.4% increase in ethanol production. All these findings prove that APQC is suitable for improving yeast resistance to high temperature during industrial bio-ethanol production.

中文翻译：

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基于人工蛋白质质量控​​制系统（APQC）构建耐热酵母提高生物乙醇产量

摘要 生物乙醇生产的一个主要挑战是开发能够在高温下持续生长的酵母。在这里，我们展示了人工蛋白质质量控​​制 (APQC) 系统在工业酿酒酵母菌株中的应用，以提高耐热性，这是生物乙醇发酵程序的关键特征。所有工程菌株在 37°C 下都表现出显着更高的生长速率和细胞活力，这赋予了更高的耐热性和更有效的葡萄糖向乙醇的转化。此外，泛素化和丙酮酸激酶 (PK) 和苹果酸脱氢酶 (MDH) 的酶活性分析表明蛋白质质量增强，表明蛋白质稳态在较高温度下得到了有效改善。来自酵母-RSP5-UBC4（泛素结合酶 E2 和泛素连接酶 E3 的组合表达）的工业材料发酵结果显示乙醇产量增加了 2.4%。所有这些发现都证明 APQC 适合在工业生物乙醇生产过程中提高酵母对高温的抵抗力。