一株有氧条件下高产乙醇酵母的筛选、鉴定及其生物学特性研究

采用平板涂布法从老白干香型大曲中获得一株有氧条件下高产乙醇酵母菌株,命名为YF1914。通过菌落形态、细胞显微结构、生理生化特性和26S rDNA D1/D2区方法对其进行鉴定,借助液体培养方式考察其乙醇耐受性、葡萄糖耐受性、乙酸耐受性、生长温度和pH等生物学特性。结果表明,该菌株为酿酒酵母(Saccharomyces cerevisiae)属于乙醇高耐受性酵母,耐受乙醇最高体积分数为18%,同时还具有较高的NaCl和葡萄糖耐受性,最高耐受质量分数分别为15%和80%,在温度为20~50 ℃和pH1~10能够生长,具有宽广的温度和pH适应性。综上,该酵母这些优良特性有利于其在未来白酒酿造方式变化中发挥作用。

Isolation and Identification of a High-yield Ethyl Alcohol Yeast in Aerobic Conditions and Its Biological Characteristics

A yeast named YF1914 with high- yield for ethyl alcohol in aerobic conditions was isolated from laobaigan- flavor Daqu by traditional microbial separation.The yeast was identified as Saccharomyces cerevisiae by colony morphology,microscopic morphology,physiological characteristics and 26S rDNA D1 /D2 sequence.The biological characteristics ethanol tolerance, glucose tolerance,acetic acid tolerance,growth temperature and pH were investigated by liquid culture method.The results showed that,the strain was Saccharomyces cerevisiae with high tolerant yeast of ethanol.The highest tolerance of ethanol volume concentration was 18%.It also had high NaCl and glucose tolerance with the highest tolerance concentration of 15% and 80%, respectively.It could grow at 20~50 ℃ and pH1~10,which indicated a wide temperature and pH adaptability.In summary,these excellent characteristies of the yeast would be conducive to its role in the future changes in Baijiu brewing methods.