酿酒酵母乙醇耐性的分子机制及基因工程改造

Ethanol tolerance in yeast: molecular mechanisms and genetic engineering

摘要:

提高工业微生物对毒性代谢产物及高温等环境胁迫因素的耐受性对工业生产具有重要的意义。发酵过程中产生的乙醇对酵母细胞的生长和代谢都具有较强的抑制作用, 是酿酒酵母的重要环境胁迫因素之一。对酿酒酵母乙醇耐性的分子机制的研究可为选育具有较强乙醇耐受性的酵母菌种提供理论基础。近年来, 通过细胞全局基因转录分析和基因功能分析, 对酿酒酵母乙醇耐性的分子机制有了更多新的认识, 揭示了很多新的与乙醇耐性相关的基因, 并在此基础上, 通过对相关基因进行过量表达或敲除, 成功提高了酵母菌的乙醇耐性。以下综述了近年来酵母菌乙醇耐性的生物化学与分子生物学机制的研究进展, 以及构建具有较高乙醇耐性的酵母菌的基因工程操作。这些研究不仅加深了对酿酒酵母乙醇耐性的机理认识, 也可为高效进行生物转化生产生物质能源奠定理论基础。

关键词:乙醇耐性, 乙醇发酵, 基因工程改造, 分子机制, 酿酒酵母

Abstract:

Improvement of stress tolerance to various adverse environmental conditions (such as toxic products, high temperature) of the industrial microorganisms is important for industrial applications. Ethanol produced by yeast fermentation is inhibitory to both yeast cell growth and metabolisms, and consequently is one of the key stress elements of brewer’s yeast. Research on the biochemical and molecular mechanism of the tolerance of yeast can provide basis for breeding of yeast strain with improved ethanol tolerance. In recent years, employing global gene transcriptional analysis and functional analysis, new knowledge on the biochemical and molecular mechanisms of yeast ethanol tolerance has been accumulated, and novel genes and biochemical parameters related to ethanol tolerance have been revealed. Based on these studies, the overexpression and/or disruption of the related genes have successfully resulted in the breeding of new yeast strains with improved ethanol tolerance. This paper reviewed the recent research progress on the molecular mechanism of yeast ethanol tolerance, as well as the genetic engineering manipulations to improve yeast ethanol tolerance. The studies reviewed here not only deepened our knowledge on yeast ethanol tolerance, but also provided basis for more efficient bioconversion for bio-energy production.

Key words:ethanol tolerance, ethanol fermentation, genetic engineering, molecular mechanism, Saccharomyces cerevisiae