Screening and Analyzing of Yeast Strains with High-yield β-glucosidase During the Natural Fermentain of Cabernet sauvignon Grapes

In order to screen β-glucosidase producing yeast srains, mature Cabernet sauvignon berries were collected from the north of Tianshan mountain in XinJiang as the raw materals.The WL medium and lysine medium, carbon and nitrogen source assimilation tests and 18S rDNA molecular identification were used to classify. The results showed that β-glycosidase enzymes yeasts strains (G8, G13, G17, G19, G21) were Saccharomyces cerevisiae. Under 14% ethanol concentration, the enzyme activity of G13 and G21 were 37.21 and 35.51 U/mL respectively. Under 24% high sugar concentration, the enzyme activity of G13 and G21 respectively were 13.87 U/mL and 11.83 U/mL which retained 30% maximum enzyme activity.At pH3.0, the enzyme activity of G13 and G21 were 19.18 and 18.31 U/mL respectively, which retained 40% maximum enzyme activity. It showed that the strains had good β-glucosidase production ability. They were expected to be applied in wine making to produce wine with regional characteristics.