Study On Screening High Quality Yeast And Biological Characteristics From Crabapple Fruit

This experiment collects crabapple fruit from Hohhot in Inner Mongolia, and uses the method that combines WL medium and conventional taxonomy to classify preliminarily for yeast on crabapple fruit surface and in fermented juice. On this basis, a representative yeast can be selected to study the biological characteristics of trials. Selecting high-quality yeast to breed for analysis and identification of PCR5.8S-ITS region/RFLP.Research results show that:through the WL medium and the conventional taxonomy methods, isolating and selecting four genera yeast from crabapple fruit in Hohhot in Inner Mongolia. They are Hanseniaspora、Pichia、Saccharomyces and Saccharomycodes; including four kinds:Hanseniaspora uvarun、Pichia kluyveri、Saccharomyces cerevisiae and Saccharomycodes ludwigii.Screening typical strains from isolated strains to do experimental study of biological characteristics. After a tolerance test analysis, the strain B2o{Saccharomyces cerevisiae) and B26(Hanseniaspora uvarun) have a prominent biological performance, especially the B20, and it can grow in the environment which is at the high temperature of45℃, the low temperature is13℃, SO2concentration is400mg/L, alcohol is18%, the sugar concentration is60%, and pH is1.5. And then, experimenting alcohol fermentation tests on the strains B20and B26, it includes the amount of residual sugar and alcohol fermentation experiments. The result is that the fermented alcohol content of strains B20is11.6%and strain B20is9.6%after10days. In residual sugar experiment, B20sugar content decreased faster than B26, and the strain the residual sugar fermentation of B20is2.4and the strain B26is3.7after10days.To sum up, strain B20is the high-quality yeast of crabapple fruit sources from Hohhot in Inner Mongolia.After B20ITS1-5.8S-ITS2rDNA sequence analysis for high quality strain which be chosen finally, results shows that the strain B20is Saccharomyces cerevisiae by establishing the systerm of the evolutionary tree.