Correlation Between Freeze-tolerance of Bakers' Yeasts and Their Cellular Content of Trehalose

面包酵母的耐冻性与其细胞内海藻糖含量的相关性

基本信息

批准号：
07680019
负责人：
KAWAI Hiroyasu
金额：
$ 1.47万
依托单位：
Nara Women's University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

This study was undertaken to clarify the correlation between freeze-tolerance of bakers' yeasts and their intracellular trehalose, a reserve carbohydrate in yeast. 1. The amount of trehalose in a freeze-tolerant cells of Torulaspora delbrueckii was higher than that of a freeze-sensitive mutant. The result suggested that the freeze-tolerance of yeast has a close relationship to its trehalose content. 2. The trehalose content of growing yeast cells was increased by a heat-shock, i.e., a temporal increase in culture temperature, and these yeast cells were found to have higher survival ratio after freeze-thawing. This indicated that intracellular trehalose of yeast has an important role to lower the freeze-injury of yeast. 3. There were found no clear correlation between trehalose content of commercial compressed bakers' yeasts belonging to Saccharomyces cerevisiae and their freeze-tolerance, but their cultured yeast cellsshowed a positive relationship between them. 4. A trehalase-deficient mutant of T.delbrueckii had a high trehalose content, while a mutant having a weak trehalose-phosphate synthetase activity had a low trehalose content. These results reflected a close relationship between freeze-tolerance and cellular content of trehalose. 5. It was found that freeze-tolerant strain had a higher trehalose-phoshpate synthetase activity and a lower neutral trehalase activity than that of freeze-sensitive strain, the results indicating that those enzyme activities were closely related to the amount of cellular trehalose and freeze-tolerance of yeast.

这项研究是为了阐明面包师酵母的冷冻耐受性与其细胞内海藻糖（酵母中的储备碳水化合物）之间的相关性。 1。在torulaspora delbrueckii的耐热细胞中的海藻糖量高于冻敏突变体。结果表明，酵母的冷冻耐受性与海藻糖含量有着密切的关系。 2。通过热震增加生长酵母细胞的海藻糖含量，即培养温度的时间升高，并且发现这些酵母细胞在冷冻后的生存率较高。这表明酵母的细胞内海藻糖在降低酵母的冷冻伤害方面具有重要作用。 3。发现属于酿酒酵母的商业压缩面包师的酵母和它们的冷冻耐受性之间没有明显的相关性，但是他们培养的酵母菌细胞共表现了它们之间的正相关关系。 4。t.delbrueckii的三酶缺陷突变体具有较高的海藻糖含量，而心形磷酸磷酸合成酶活性的突变体具有较低的心形核含量。这些结果反映了冰冻耐受性和海藻糖的细胞含量之间的密切关系。 5。发现耐耐受耐药菌株具有比冰冻敏感性菌株更高的海藻糖 - 磷酸合成酶活性和低的中性三酶活性，结果表明这些酶活性与细胞杂种和冻结的量密切相关。 - 酵母的耐受性。