Alcohol fermentation is a key process in wine, beer, alcoholic beverage production, bioethanol production by means of carbohydrate sources, and food industry byproducts. There are three key points in these kinds of processes determining their efficiency; enzymatic cellulose lysis into simple sugar molecules, alcohol fermentation rate, and ethanol tolerance of yeast cells. The first process is usually carried out by either the use of pure cellulolytic enzymes, which is a high cost procedure, or by the production of these enzymes from cellulolytic bacteria and filamentous fungi. Lately, Saccharomyces cerevisiae and several other yeasts were genetically modified to express recombinant cellulases in media or display them on the cell surface. Many studies have indicated that the genetic engineering of yeast cells can be a useful approach in increasing the alcoholic fermentation rate as well as their ethanol tolerance. These modifications could be the overexpression of a key protein using a strong promoter or the modification of a specific domain or amino acid which can also lead to the desired outcome. This review focuses on the modifications of a single protein and/or pathways that can lead to the augmentation of ethanol tolerance and alcoholic fermentation efficiency of Saccharomyces cerevisiae .

中文翻译：

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影响酵母乙醇耐受性和发酵效率的因素

酒精发酵是葡萄酒、啤酒、酒精饮料生产、利用碳水化合物来源生产生物乙醇和食品工业副产品的关键过程。在这些类型的过程中，有三个关键点决定了它们的效率；酶促纤维素裂解成单糖分子、酒精发酵率和酵母细胞的乙醇耐受性。第一个过程通常通过使用纯纤维素分解酶进行，这是一个高成本的过程，或者通过从纤维素分解细菌和丝状真菌生产这些酶来进行。最近，酿酒酵母和其他几种酵母经过基因改造，可以在培养基中表达重组纤维素酶或在细胞表面展示它们。许多研究表明，酵母细胞的基因工程可以成为提高酒精发酵率和乙醇耐受性的有用方法。这些修饰可能是使用强启动子过度表达关键蛋白质，也可能是对特定结构域或氨基酸的修饰，这也可能导致预期的结果。本综述侧重于单一蛋白质和/或途径的修饰，这些修饰可导致酿酒酵母乙醇耐受性和酒精发酵效率的增强。