Screening And Breeding Of Yellow Wine Yeast To Low The Concentration Of Biogenic Amines In The Chinese Yellow Wine

Biogenic amines are low molecular weight and the important indicator of food quality and safety that are formed by the descarboxylation reaction from corresponding free amino acids by amino acid decarboxylase from microorganisms. Yellow Wine is Chinese national wine, which belongs to the the world’s three brewing wine (Yellow Wine, one of the Wine and beer). The fermentation process of the rice wine is an open and mixed bacterium process. Because of the exitence of a large number of amino acids and abundant microbial, biogenic amines could be generated during the rice wine brewing process.In this paper, we mainly focused on the Yellow Wine yeast and screened Yellow wine yeast with low PrA activity. The researches on the effects of protease A to the formation of biogenic amines in Yellow Wine brewing are as follows.(1) The screening of low protease A activity of the rice wine yeast strains of the proteolytic circle plate through the ultraviolet mutagenesis. The after screening test results showed that the protease A activity was not significantly reduced of the ultraviolet mutagenesis strains obtained. So new mutagenesis methods and screening conditions for low protease A activity strains need to be studied.(2) The mutants RY1-a-PEP4and RY1-a-PEP4was constructed by the recombinant plasmid pUC-ABK (The recombinant plasmid pUC-ABK was constructed with the DNA fragments A and B which were from each side of the prosequence, KanMX gene was subsequently inserted into the plasmid pUC19). The recombinant diploid RY1-PEP4was obtained after the fusion of the purified RYl-a-PEP4and RYl-a-PEP4haploids.(3) The Yellow Wine fermentation experiments were conducted with the RY1> RY1-a、RY1-α、RY1-a-PEP4、RY1-a-PEP4and RY1-PEP4. The fermentation results showed that the biogenic amines contents were decreased obviously of the mutant RY1-PEP4knocked out the prosequence of PEP4. The contents of tryptamine, cadaverine and putrescine were decreased by60.879、23.86%and50.75%. The other fermentation characteristics had no significant changes. Our results provide a new strategy to minimize biogenic amines concentration in the Chinese rice wine brewing.