山西榆次后沟堡子酒酒曲中优势酵母菌的分离鉴定

从榆次后沟堡子酒的酒曲中分离纯化酵母菌,得到了2株菌株S1和S2,并采用同化碳源试验、同化氮源试验、硝酸盐利用试验、生成类淀粉试验以及酵母菌的耐酒精性试验对其特性进行探索,结果如下:S1和S2菌株均不能利用甲醇作为碳源,对葡萄糖和蔗糖的利用情况也不同,S1菌株对葡萄糖的利用率最高,蔗糖次之;S2菌株对葡萄糖和蔗糖的利用情况相似;在葡萄糖和蔗糖利用方面,S1菌株较S2菌株同化率高。S1和S2菌株均能在所加氮源周围形成同化圈,表明二者对氮源的利用率很高;在硝酸盐利用试验中,S1和S2菌株所得结果均呈阳性反应,表明二者可以分泌大量胞外酶分解利用细胞外分子中的糖和蛋白质;S1和S2菌株均不能产生类淀粉物质;两株菌对酒精的耐受性也不相同,在同等酒精浓度下,S1菌株较S2菌株长势良好,12%为最适酒精度。

Isolation and Identification of Yeast from Hougou Buzi Wine of Yuci Shanxi Province

Two yeast strains named S1 and S2 were isolated and purified from Hougou Buzi wine of Yuci.The tests on carbon assimilation,nitrogen assimilation,nitrate utilization,to generation amylum,and alcohol resistance were conducted to explore its properties.The results were as follows: S1 and S2 strains could not use methanol as carbon source.S1 strain had the highest use rate of glucose followed by sucrose,similar to S2 strain,but the assimilation rate of S1 strain was higher than that of S2 strain in the utilization of glucose and sucrose.S1 and S2 strains also had higher nitrogen assimilation rate.The results of S1 and S2 strains in the nitrate utilization test were all positive,which indicated that they could secret many extracellular enzymes to utilize the sugar and protein out of cells.Both S1 and S2 strains could not produce amyloid substances.The growth of S1 strain was better than that of S2 strain under the same alcohol concentration,and 12% was the best alcohol concentration.