紫外诱变选育耐酸酵母菌株及其特性研究

以实验室保存的耐酸酵母菌株YM1-1为出发菌株，在其对数生长期进行紫外诱变处理，经过三级筛选后，最终筛得一株在pH 1.8强酸环境中仍可存活的突变菌株YM1-1E。在其特性研究中发现，菌株YM1-1E最适生长温度和pH值分别为36 ℃和5.5，能耐受500 mg/L SO2、14%乙醇和65%的葡萄糖溶液。突变菌株YM1-1E在pH值为2.5的发酵培养基中发酵6 d后，发酵液酒精度为4.5%vol，糖醇转化率为46.39%，可溶性固形物含量为9.7%，较出发菌株YM1-1相比，产酒精能力提升了25%。

Breeding of acid-resistant yeast strain by UV mutation and its characteristics

Using acid-resistant yeast strain YM1-1 preserved in laboratory as original strain, strain YM1-1 during the logarithmic growth phase was treated with ultraviolet mutagenesis. A mutant strain which could still survive in pH 1.8 acid environment was screened and obtained by three level screening. The results of its characteristic research showed that the optimum growth temperature and pH of strain YM1-1E were 36 ℃ and 5.5, respectively, and could tolerate 500 mg/L SO2 , 14% alcohol and 65% glucose solution. Mutant strain YM1-1E was fermented in a fermentation medium with pH 2.5 for 6 d, then the alcohol content of fermentation broth was 4.5%vol, the conversion rate of sugar and alcohol was 46.39%, the soluble solid content was 9.7%. Compared with original strain YM1-1, the alcohol production capacity of mutant strain YM1-1E was increased by 25%.