In this thesis,the high-yielding ethyl acetate yeast and lactic acid degrading bacteria in the brewing process of Light-Flavored Baijiu were taken as the research objects,and the interaction and metabolism differences...In this thesis,the high-yielding ethyl acetate yeast and lactic acid degrading bacteria in the brewing process of Light-Flavored Baijiu were taken as the research objects,and the interaction and metabolism differences of microorganisms in the co-cultivation process were compared through the establishment of mixed-bacteria fermentation systems with different ratios,and provide a theoretical basis for regulating flavor formation dur-ing Light-Flavored Baijiu fermentation.The main research content and results were as follows:During fermen-tation,high-yielding ethyl acetate yeast(J2)inhibited the growth of lactic acid-degrading bacteria(R12),but its development was not affected by lactic acid-degrading bacteria;untargeted metabolomics analysis indicates that the inhibitory effect of high-yield ethyl acetate yeast on lactic acid-degrading bacteria was achieved through many different metabolic pathways.Among them,the cysteine and methionine metabolism pathway has the strongest metabolic effect.High-yield ethyl acetate yeast secretes substances such as cystathionine,n-butylamine,tryptophan,alanine,and triethyl orthoacetate into the extracellular space through these metabolic pathways,inhibiting the growth of lactic acid-degrading bacteria.Lactic acid-degrading bacteria were able to influence the metabolism of ethanol,organic acids,and flavor substances in high-yield ethyl acetate yeast.Lactic acid-degrading bacteria could promote the metabolism of ethanol,citric acid,succinic acid,and tartaric acid in high-yield ethyl acetate yeasts,effectively lowering the content of ethyl lactate with an appropriate proportion of inoculation;it also stimulates the metabolism of some new esters,alcohols,aldehydes,and change the content of some esters and phenols in the co-culture system due to the metabolism of lactic acid degrading bacteria themselves.展开更多
基金funded by the General Youth Fund Project of Shanxi Province(20210302124511)Research and Development Projects(01130122090116)Xinghuacun College Open Project Foundation(XCSXU-KF-202306,XCSXU-KF-202313,XCSXU-KF-202317,XCSXUKF-202328).
文摘In this thesis,the high-yielding ethyl acetate yeast and lactic acid degrading bacteria in the brewing process of Light-Flavored Baijiu were taken as the research objects,and the interaction and metabolism differences of microorganisms in the co-cultivation process were compared through the establishment of mixed-bacteria fermentation systems with different ratios,and provide a theoretical basis for regulating flavor formation dur-ing Light-Flavored Baijiu fermentation.The main research content and results were as follows:During fermen-tation,high-yielding ethyl acetate yeast(J2)inhibited the growth of lactic acid-degrading bacteria(R12),but its development was not affected by lactic acid-degrading bacteria;untargeted metabolomics analysis indicates that the inhibitory effect of high-yield ethyl acetate yeast on lactic acid-degrading bacteria was achieved through many different metabolic pathways.Among them,the cysteine and methionine metabolism pathway has the strongest metabolic effect.High-yield ethyl acetate yeast secretes substances such as cystathionine,n-butylamine,tryptophan,alanine,and triethyl orthoacetate into the extracellular space through these metabolic pathways,inhibiting the growth of lactic acid-degrading bacteria.Lactic acid-degrading bacteria were able to influence the metabolism of ethanol,organic acids,and flavor substances in high-yield ethyl acetate yeast.Lactic acid-degrading bacteria could promote the metabolism of ethanol,citric acid,succinic acid,and tartaric acid in high-yield ethyl acetate yeasts,effectively lowering the content of ethyl lactate with an appropriate proportion of inoculation;it also stimulates the metabolism of some new esters,alcohols,aldehydes,and change the content of some esters and phenols in the co-culture system due to the metabolism of lactic acid degrading bacteria themselves.
