The Study on the Mechanisms of Freeze-tolerance of Yeast in Frozen-dough.

冷冻面团中酵母菌的耐冻机制研究。

• 批准号: 05680021
• 负责人: KAWAI Hiroyasu
• 金额: $ 1.28万
• 依托单位: Nara Women's University for Scientfic Research
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05680021/
• 关键词: Freeze-tolerant yeast; Freeze-sensitive yeast; Torulaspora delbrueckii; Freeze-tolerance of yeast; Mechanism of Freeze-tolerant of Yeast; Frozen-dough; 冷凍障害; ピューロチオニン

This study was undertaken to clarify the mechanism of freeze-tolerance of yeast by analyzing the composition of lipid and the content of intracellular trehalose of a freeze-tolerant yeast Torulaspora delbrueckii D2-4 and a freeze-sensitive strain 60B3 which was derived from D2-4 by mutation. It was found that the total content of phospholipid and its composition together with the ratio of sterol to phospholipid of D2-4 differed apparently from those of 60B3, the results indicating that the difference of lipid composition between the two strains may attribute to reflect the freeze-sensitivity of yeast. Then, the relation between freeze-tolerance and trehalose content of yeast cells was investigated. It was observed that the intracellular content of trehalose of D2-4 was higher than that of 60B3, and that the freeze-tolerance ratio changed in parallel with the change of trehalose content occurred under various growth conditions. The result suggested the participation of trehalose in yeast cells with their freeze-tolerance. The trehalose content of compressed bakers' yeast commercially available for a freeze-dough process varied with the specimens, but their survival ratio after freezing at -20ﾟC for 1 week was found to depend on their trehalose content, thus an important role of intracellular trehalose to protect yeast cells from freeze-injury was suggested.

本研究通过对一株耐冻酵母D2-4和一株从D2-4诱变而来的冻敏菌株60B3的脂肪组成和胞内海藻糖含量的分析，探讨了酵母的耐冻机理。结果表明，D2-4菌株与60B3菌株在磷脂总量、磷脂组成及甾醇/磷脂的比值上存在明显差异，说明这两种菌株的磷脂组成的差异可能反映了酵母对冷冻的敏感性。研究了酵母细胞的耐冻性与海藻糖含量的关系。结果表明，D2-4菌株胞内海藻糖含量高于60B3菌株，且在不同生长条件下，其耐冻性与海藻糖含量的变化是平行的。结果表明，海藻糖参与了酵母细胞的耐冻性。商业上可用于冷冻面团过程的压缩面包酵母的海藻糖含量因样品而异，但在-20ﾟC下冷冻1周后的存活率取决于其海藻糖的含量，因此，细胞内的海藻糖对保护酵母细胞免受冷冻损伤具有重要作用。

项目成果

YOKO MURAKAMI: "Lipid composition of a Freeze-tobrant yeast,Torulaspora delbrueckii" Appl.Microbiol.Biotechnol.(未定). (1995)

YOKO MURAKAMI：“冷冻酵母的脂质成分，Torulaspora delbrueckii”Appl.Microbiol.Biotechnol.（待定）。

Y.Murakami et al: "Induction of Freeze-sensitive Mutants from a Freeze-tolerant yeast,Torulaspora delbrueckii" Bioscience,Biotechnology of Biochemistry. 58. 206-207 (1994)

Y.Murakami 等人：“从耐冷冻酵母中诱导冷冻敏感突变体，Torulaspora delbrueckii”生物科学，生物化学生物技术。

河合弘康: "パン酵母の冷凍障害と冷凍耐性酵母" 化学と生物. 31. 374-381 (1993)

Hiroyasu Kawai：“面包酵母和抗冻酵母的冷冻损伤”化学与生物学 31. 374-381 (1993)。

YOKO MURAKAMI: "Lipid Composition of a Freeze-tolerant yeast,Torulospora delbrueekii" Appl.Microbiol.Biotechnol.(未定). (1995)

YOKO MURAKAMI：“耐冷冻酵母的脂质成分，Torulospora delbrueekii”Appl.Microbiol.Biotechnol.（待定）。

YOKO MURAKAMI: "Induction of Freeze-sensitive Mutauts from a Freeze-toleraut yeast,Torulaspora delbrueckii" Biosci.Biotech.Biochem.58. 206-207 (1994)

YOKO MURAKAMI：“从耐冻酵母中诱导冷冻敏感突变体，Torulaspora delbrueckii”Biosci.Biotech.Biochem.58。