Study On Yeasts Of Differentages Of Vinyards

Alcoholic fermentation is one of the main stages in wine production..Yeasts play a critical role during winemaking. The diversity and the kinds of the yeast micropopulation contribute to the wine sensory quality significantly.Lots of factors can affect wine yeasts, especially the age of vineyard. However, few papers on this research field were published at home and abroad. So it is essential to study the relations between wine-related yeasts and the ages of vineyard.This study choose Changli region in Hebei china which is called"town of vintage grape of china".By dint of zoology condition of Changli, classify wine yeasts of typical species by WL medium. Yeast species assessment was carried out by amplification and digestion of a region of the ribosomal RNA gene repeat unit.Then the grape and compositions of corresponding vineyard are analyzed for searching difference.The results were as follows:1. 280 wine-related yeasts of different ages of vineyard of syrahs were classed by WL Nutrient Medium indicates that there are 7 types of yeast strains ;268 wine-related yeasts of different ages of vineyard of Sc are also 7 types.2. Identity analysis based on the sequence of 5.8-ITS region of the strains indicated that there are 7 species wine-related yeasts of different ages of vineyard of syrahs : Issatchenkia terricola,Cryptococcus flavescens,Hanseniaspora uvarum,Saccharomyces cerevisiae,Cryptococcus kuetzingii,Rhodotorula acuta,Pichia kluyveri; there are 7 species wine-related yeasts of different ages of vineyard of cabernet sauvignon: Candida soborsa,Cryptococcus flavescens,Hanseniaspora uvarum,Saccharomyces cerevisiae,Cryptococcus kuetzingii,Rhodotorula acuta,Pichia kluyveri.As the age adding,diversity is on quantity and species has no difference of small age interval, diversity is on quantity and species of big age interval.Dominant species: Saccharomyces cerevisiae,Hanseniaspora uvarum.As the age adding, dominant status of Saccharomyces cerevisiae is up, Hanseniaspora uvarum is down.3. By experiment analysis ,the same species of different vineyard yeasts vary in the courseof spontaneous fermentation on species and quantity; syrahs: Issatchenkia terricola,Cryptococcus flavescens,Hanseniaspora uvarum,Saccharomyces cerevisia,Pichia kluyveri.Sc: Candida.soborsa,Hanseniaspora uvarum,Saccharomyces cerevisiae,Pichia kluyveri. 4. Yeasts species of skin has no diversity,quantity has diversity. yeasts species of skin of Syrahs and Sc are the same: Cryptococcus flavescens,Pichia kluyveri,Cryptococcus kuetzingii,dominant species are Cryptococcus flavescens;yeasts species of soil has also no diversity, Syrahs and Sc are the same: Cryptococcus flavescens,Rhodotorula acuta,Cryptococcus kuetzingii, dominant species are Cryptococcus kuetzingii.5. The main grape nutrition of different vineyards (Total sugar,total nitrogen,total acid,pH,amino acid) are different; discrepancy is markedness or not related with interval of grape ages.the main compositions of soil (Organic material,total nitrogen,pH ) have no diversity.By this study,the concrete study on yeasts of different ages of vineyard reveals the relations between age of grape and wine yeast that using yeast of big age vineyard can quicken up fermentation,cut fermentation cycle,and in favor of filtration of yeast strains .