乙醇耐受性提高的酿酒酵母基因工程菌株的构建

The construction of genetic engineering strain of Saccharomyces cerevisiae to improving ethanol tolerance

将酿酒酵母转录激活因子Msn4基因置于组成型强启动子PGK下,构建重组整合表达质粒YPKRMsn4,r DNA介导整合到受体菌酵母工业菌株Y49的染色体中,筛选得到酿酒酵母菌YM-27。该菌过量表达酿酒酵母转录激活因子Msn4基因,乙醇耐受性有较大提高。构建的酿酒酵母工程菌运用在木薯乙醇工业生产中,可克服浓醪发酵中后期酵母菌受高浓度乙醇抑制而发酵活力不足的问题,可应用于乙醇浓醪发酵,为进一步构建具有高潜能的优良菌株奠定基础。

The Msn4 gene encoding transcription factor is related to ethanol tolerance. To improve ethanol production in Saccharomyces cerevisiae, an integration plasmid YPKR-Msn4 with Msn4 gene under the PGK promoter was constructed using standard recombinant DNA technology. The plasmid was transformed and the Msn4 gene was integrated into genome r DNA locus of S. cer-evisiae Y49, by which the genetic engineering strain YM-27 was obtained. The results showed that the strain YM-27 overexpressed the gene of Msn4, and its ethanol tolerance was significantly improved. The recombinant stain of S. cerevisiae constructed through genetic engineering in this work possesses the properties of high tolerance and adaptation to high-gravity and high concentration of ethanol, which lead to low fermentation activities during post-fermentation. These properties enable it to overcome the problem of low activity. The recombinant stain of S. cerevisiae has potential application in high concentration ethanol fermentation from cassava to produce ethanol, which will bring obvious economic benefit in industry.