Screening and breeding of freeze-tolerant baker's yeast

耐冻面包酵母的筛选与选育

• 批准号: 61580065
• 负责人: KAWAI Hiroyasu
• 金额: $ 1.41万
• 依托单位: Nara Women's University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61580065/
• 关键词: Freeze-tolerant baker's yeast; Screeining of freeze-tolerant yeast; Breeding of freeze-tolerant yeast by cell fusion; S.cerevisiae; 耐糖性酵母; 冷凍耐性酵母の検索

This study was undertaken to isolate freeze-tolerant baker's yeasts from natural sources and to breed them by the method of cell fusion. In the first part of this report, we selected several strains of freeze-tolerant yeast from soil and foods which were grown on a medium containing high concentration of sucrose. Two strains of yeast, No. 5 and No. 9-1, which were isolated from soil, had a strong fermentative activity similar to the commercial baker's yeast as well as high freeze-tolerance after pre-fermentation of dough. These yeasts were identified as Saccharomyces species from their cultural and physiological nature, Furthermore, the strain No. 5, an ascosporogenous yeast, was able to ferment maltose and it seemed to be industrially available for breadmaking by freeze-dough method. In the second part of this report, the cell fusion method was applied to obtain freeze-tolerant yeasts with high fermentative activity between Saccharomyces cerevisiae and S. rosei. It was found that all the fusants had relatively high fermentative activity, but retained predominantly the nature of S. cerevisiae than S. rosei, that is, their freeze-tolerance were poor as compared to the paraent strain S. rosei.

本研究从天然来源中分离出耐寒的面包酵母，并采用细胞融合的方法进行了培养。在本报告的第一部分中，我们从土壤和食物中选择了几株耐冻酵母，这些酵母生长在含有高浓度蔗糖的培养基上。从土壤中分离得到的酵母5号和9-1号，对面团进行预发酵后，发酵活性与商品面包酵母相似，且具有较高的抗冻性。这些酵母菌从培养和生理性质上被鉴定为酵母菌种。此外，5号菌株是一种子囊孢酵母，能够发酵麦芽糖，似乎可以用冷冻面团法制作面包。在本报告的第二部分中，采用细胞融合方法获得了介于酿酒酵母和玫瑰酵母之间具有高发酵活性的耐冻酵母。结果表明，所有融合体均具有较高的发酵活性，但其主要保留了酿酒酵母的特性，即抗冻性较母本酿酒酵母差。