Identification And Characterization Of Yeasts Isolated From Liquor Fermentations

In today’s increasingly severe deterioration of global environment and energy crisis. As a sort of green energy, the ethanol is becoming the focus of the national energy development. Yeast, as an essential microbial resources in producing ethanol,which plays an important role in the process of production of ethanol.So this project will conduct research from the following three aspects.First, purification and preliminary identification. The experimental samples were collected from9regions of Sichuan province.This experiment will vinasse dilution certain concentration in the coating containing bacteriostatic agent YEPD solid culture medium.One hand,yeast strains were Picked off the typical characteristics. Each sample select one representative strain, a total of19strains were sleceted for further identification. Preliminary identification that and all strains were yeasts, which belong to4kinds speies and were Saccharomyces cerevisiae, Pichia galeiformis, Meyerozyma guilliermondii, Debaryomyces nepalensis.Second, molecular identification of yeasts.Representative strains were identificated by26S rDNA D1/D2region molecular identification, further validate the results on the level of molecular biology.Analyzing of the tested strains’rDNA ITS sequence. The result showed that the17strains identified to species on the molecular level of ITS, and the remaining two were identified to genus. And preliminary analysis of phylogenetic relationship between the representative strains by phylogenetic tree. The result of M13and （GTG）5fingerprint analysis of the representative strains showed that yeasts from different samples had abundant genetic diversity.Third, characteristics of yeast. By resistance of ethanol, furfural, HMF and high temperature experiments were done to study the characteristics of tested strains. Also describe the growth curves of different dominant fungus wrer analysed to compare the different cultures. Among them, the Saccharomyces cerevisiae QWD₀1has the strongest capabilities of tolerance, which could withstand10%ethanol,30mM furfural,90mM5-hydroxymethyl furfural.This paper enrichs the microorganisms library data resources of fuel ethanol,providing important strains resources for further study of molecular mechanism or other special features strains using protoplast fusion and integration of modern biotechnology issued valuable engineering strain...