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.

本研究通过分析耐冻酵母德氏圆酵母D2-4和源自D2-的冷冻敏感菌株60B3的脂质组成和胞内海藻糖含量，阐明酵母的耐冻机制。发现D2-4的磷脂总含量及其组成以及甾醇与磷脂的比例与D2-4有明显差异。 60B3，结果表明两个菌株之间的脂质组成的差异可能反映了酵母的冷冻敏感性。然后，研究了酵母细胞的冷冻耐受性和海藻糖含量之间的关系。 D2-4的海藻糖含量高于60B3，并且在不同的生长条件下，耐冻性比率随海藻糖含量的变化而变化。海藻糖在酵母细胞中的参与及其冷冻耐受性 商业上可用于冷冻面团加工的压缩面包酵母的海藻糖含量随样本的不同而变化，但在-20℃冷冻1周后它们的存活率被发现。取决于其海藻糖含量，因此表明细胞内海藻糖在保护酵母细胞免受冻损伤方面发挥着重要作用。

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 et al: "Lipid composition of a Freeze-tolerant Yeast, Torulaspora delbrueckii and Its Freeze-sensitive Mutant." Appl. Microbiol. Biotechnol.(in presentation.).

Yoko Murakami 等人：“耐冷冻酵母、德氏圆酵母及其冷冻敏感突变体的脂质成分。”