Method for producing freeze resitant yeast

摘要

Freeze resistant baker's yeast is produced by increasing a ratio of unsaturated fatty acid content to total fatty acid content of a baker's yeast cell to 80% or more. The ratio is increased by, for example, enhancing delta-9-fatty acid desaturase activity in the cell. The present invention elucidates a genetic trait determining freeze resistance of yeast, thereby providing a novel breeding method of practical freeze resistant yeast strains.