青海东部野生酵母菌株抗性及发酵特性研究

Research on Stress Resistance and Fermentation Characteristics of Wild Yeast Strains in Eastern Qinghai

以分离自青海的97株野生酵母菌株为材料,通过杜氏管发酵法初筛出35株发酵力强、有香味的酵母菌株,对其抗性和发酵特性进行研究。结果表明,35株酵母菌对SO2具有高度的抗性,大部分菌株在SO2浓度为600mg/L时仍可正常生长并发酵;有7株耐NaCl高达120.0g/L,菌株QXN2在160.0g/L的浓度下仍可正常生长并发酵;但大多数菌株的酒精耐受力弱,仅有6株可耐12%vol的乙醇,但已不能发酵产气;部分酵母菌株的耐温性较高,如菌株QHL4、QXS1、QJD12可耐受55℃高温;pH耐受范围在2.5～12.0之间,大部分菌株可在600g/L的葡萄糖溶液中生长,其中9株仍可发酵产气。这9株发酵力较好且产香酵母的酒精发酵结果表明,4株产酒精度为0,具有浓郁的芳香;4株产酒度在2.1%vol～2.4%vol之间,且残糖较低,有浓郁果香。优良酵母菌株有望应用于面包生产、无醇饮料的开发、工业废水处理等领域。

97 wild yeast strains were collected from Qinghai as the experimental materials. 35 strains with high fermentation capacity and strong aroma were screened out by Durham tube method. Then the stress resistance and fermentation characteristics of the 35 strains were studied and the results showed that all the 35 strains could grow in high concentration of SO2, most strains grew and fermented normally as the concentration of SO2 was 600 mg/L, 7 strains could tolerate 120.0 g/L NaCl and strain QXN2 could grow and ferment normally as NaCl concentration was 160.0 g/L, however, most strains had weak alcohol-resistance （only 6 strains could tolerate 12 %vol alcohol but could not ferment）, some strains including QHL4, QXS1, QJD12 could tolerate temperature at 55 ℃, the strains pH tolerance range was between 2.5～12.0, most strains could grow in 600.0 g/L glucose solution and 9 strains of them could still ferment, the 9 excellent strains were screened out and their fermentation results showed that the alcoholicity of 4 yeast strains was zero, but all of them had strong aroma, the alcoholicity of 4 strains was between 2.1 %vol～2.4 %vol with lower residual sugar and fruit fragrant. The excellent yeast strains could be used for bread baking, the development of non-alcohol beverage, and the treatment of industrial waste water etc.