FKS家族基因对酿酒酵母压力耐性的影响

Effects of FKS Family Genes on the Ability of Saccharomyces cerevisiae Stress Resistance

FKS作为1,3-β-葡聚糖合成酶基因家族,对维持酿酒酵母细胞壁有重要作用。为探究FKS家族基因对酿酒酵母细胞抗逆性及其合成乙醇的影响,通过同源重组的方法分别构建了FKS1、FKS2和FKS3基因的缺失菌株,并比较重组菌株和原始菌株的性能差异。结果表明,FKS1缺陷菌株细胞壁的1,3-β-葡聚糖含量低于原始菌株60%,生长性能、抗胁迫性以及合成乙醇能力都较差。FKS3缺陷菌株的生长性能和胁迫性能与原菌株相似,在发酵环境中抵抗外界环境能力和合成乙醇能力优于原始菌株。因此,FKS1基因对维持酵母细胞活性和抗逆有重要作用,而FKS3基因对抗逆有负面作用。

The FKS family genes which encoded 1,3-β-glucan synthase are important to maintain the integrity of Saccharomyces cerevisiae cell wall.To illustrate the functions of FKS family genes on the ability of S.cerevisiae to tolerate the environmental stresses and ethanol production,the FKS1,FKS2,and FKS3 knocked out strains were constructed by homologous recombination,then the physiological properties of wile-type strain and mutant strains were measured and compared.The results showed that the content of 1,3-β-glucan in cell wall of the FKS1 knocked out strain was 60%lower compared to the wild type.The knockout of FKS1 gene also weakened the abilities of growth,stress resistance and ethanol production for S.cerevisiae.Furthermore,the growth and stress resistance abilities of FKS3 gene knocked out strain were similar to those of the wild-type strain,however its abilities to tolerate the fermentation environment and to produce ethanol were better than those of the wild-type strain.Therefore,the FKS1 gene was important for S.cerevisiae to keep the cells activity and to resist the environmental stresses while the FKS3 gene negatively influenced the ability of S.cerevisiae to resist outer stresses.