酒醅中优势酵母菌的筛选及生理生化特性分析

Screening and Analysis of Physiological and Diochemical Characteristics of Dominant Yeast of Fermented Grains

从发酵25d的浓香型酒醅中筛选出三株优势酵母菌,结合菌落特征、细胞形态和生理生化分析结果,根据《酵母菌的特征与鉴定手册》初步鉴定YS为酿酒酵母、YY为季也蒙毕赤氏酵母、YB为陆生地霉。三株酵母菌代谢酸、酯能力有一些差异,但主要代谢产物均为庚酸乙酯和乙酸。YS、YY、YB最适p H范围分别为5.0~6.0、5.5~7.0、4.0~6.0,YS、YY、YB最适生长温度范围分别为28~30℃、30~32℃、28~30℃。

Three strains of dominant yeast were screened from the 25 d fermented Luzhou flavor grains. According to the ＂Characteristics and identification of yeasts＂ and combined the characteristics of the colony, cell morphology and physiological biochemical analysis,the YS,YY, and YB were identified as Saccharomyces cerevisiae, Pichia guilliermondii and Geotrichum terrestre respectively through preliminary identification. There are some differences in the metabolic acid and ester ability among the three strains of yeast. But the main metabolites were ethyl oenanthate and acetic acid. The optimum p H values of YS, YY, and YB were 5.0~6.0, 5.5~7.0, 4.0~6.0, respectively. The optimum growth temperature of YS, YY and YB were 28~30℃, 30~32℃ and 28~30℃ respectively.