5.8S-ITS Region RFLP Analysis Of Vitis.amurensis Rupr Wine Yeasts In Northeast China And Fine Wine Yeast Strains Selection

Wine yeasts were the important microorganism during vinification. Wine yeasts diversity and identification are the foundation for further fine wine yeast selection. The yeasts which from grape variety original region can present variety characteristic, soil feature and region property.Due to the low total sugar and high acidity Vitis.amurensis Rupr grape possessed and low temperature during fermentation season, So autochthonic yeast must be selected to adapt to this factors and also to solve the stuck fermentation because the ordinary wine yeast can not endure low pH and high acidity must condition.The composition of wine yeast populations, presented during spontaneous fermentation and grape berry surface of Vitis.amurensis Rupr wine from the Northeast China was studied. Yeast species assessment was carried out by amplification and digestion of a region of the ribosomal RNA gene repeat unit. All of the Saccharomyces strains used to select wine yeast can endure low pH, high acidity must condition and develop grape berry feature etc.The results were as follows:1. This work shows Wallerstein Laboratory Nutrient Agar (WL medium) was strengthened for use in wine fermentation to observe yeast populations and useful in wine yeast identification.2. 298 wine related yeasts were isolated from the Spontaneous fermentation of V. amurensis Rupr. Yeast species assessment was carried out by WL medium. 11 unique colony morphologies were identified.3. By analysis of the restriction pattern of amplified 5.8S-ITS rRNA gene (RFLP) with the enzyme HinfI, HaeIII and HhaI, respectively, 19 different genotypes were existed in fermentation. Thereinto, pattern 6 was Dekkera anomala that was the main species on the surface of the V. amurensis Rupr berry and pattern 19 was Saccharomyces cerevisiae. PCR product sizes vary from 490 to 880 bp.4. By analysis of the restriction pattern of amplified 5.8S-ITS region (RFLP) 5 different genotypes were found in grape berry surface. 5. After 79 Saccharomyces strains 3 steps selection, the fine wine yeast strain named 1-H-3 at the same time with tolerance of low temperature and low pH had received. The wine which fermented from 1-H-3 has an advantage over dry yeast SK102 in final wines sensory aspect and aroma.After this study, the preliminary ideas of Vitis.amurensis Rupr grape wine yeast diversity in northeast China were established. The fine wine yeast named 1-H-3 which could tolerance low temperature and low pH had received at the same time with final wines fine sensory and aroma.