Abstract:Freeze-tolerance is a necessary characteristic of yeast used in frozen dough. Target freeze-tolerant strain was screened using liquid fermentation (LF) medium method, applied for frozen dough production, and the relationship between the content of intracellular compounds and cell survival and relative fermentation ability in different yeasts was analyzed. The isolated strain was identified mainly by morphologic observation and 26S rDNA gene sequence analysis. The results showed that seven strains were selected from four various sourdoughs, their freeze-tolerance rate ranged from 9%~86%, and relative fermentation ability ranged from 9%~67%. Two strains, Y-3 and H-1, had highest survival ratio of 86% and highest relative fermentation ability of 67%, respectively. The result of correlation analysis showed that survival ratio was significantly positively correlated with trehalose, glycerol , proline level, but negatively correlated with arginine, aspartic acid,glutamate and relative fermentation ability; relative fermentation ability was significantly positively correlated with aspartic acid and glutamate, and negatively correlated with trehalose, glycerol, proline and arginine level. Strain Y-3 was identified as Debaryomyces hansenii, and strain H-1 was identified as Saccharomyces cerevisiae. Comprehensive consideration of freeze-tolerance, fermentative ability and safety, mixed fermentation of Y-3 and H-1 will be used to produce of frozen dough.