酿酒酵母α-磷酸甘油脱氢酶变异株的鉴定及其高渗敏感性状的遗传分析

CHARACTERIZATION OF α-GLYCEROPHOSPHATE DEHY DROGENASE (α-GPD) VARIANT AND GENETIC ANALYSIS OF ITS OSMOTIC SENSITIVITY IN YEAST SACCHAROMYCES CEREVISIAE

本室检测到一株酿酒酵母α-磷酸甘油脱氢酶(α-glycerophosphate dehydrogenase,简称α-GPD)变异株,在所试条件下,变异株的α-GPD酶活比野生型菌株低5倍多。遗传分析表明,该变异株的α-GPD变异是由单一结构基因发生突变,使其所编码的α-GPD分子的构象发生变化而导致酶活显著下降,这也就使它在高渗条件下不能正常生长而表现为高渗敏感菌株。但在一般培养条件下,变异株的呼吸能力、生长量和发酵力与野生型菌株均无明显差异。此外,本文还对酿酒酵母的α-GPD活性与高渗敏感性状的关系进行了讨论。

The strain H 516-18, a α-GPD variant in Saccharomyces cerevisiae, has been detected in our laboratory. Its activity is about five times less than that of the wild strain under culture conditions tested. The results of genetic analysis show that the α-GPD variant is originated from mutation of a single structural gene of the coded molecular conformation of the α-GPD, and this makes the variant cannot grow in high osmotic media. Therefore, it appears as a high osmotic sensitive variant.While, there are no marked differences of respiratory activity, growth rate and fermentability between the variant end the wild strain in general cultural conditions. In addition, the relationship between α-GPD activity and high osmotic sensitivity in Saccharomyces cerevisiae was also discussed in this paper.