Ethanol stress is an important environmental factor that affects physiological metabolism and aroma-producing capacity of yeast during the brewing process of alcoholic products.To explore the mechanisms of the growth ...Ethanol stress is an important environmental factor that affects physiological metabolism and aroma-producing capacity of yeast during the brewing process of alcoholic products.To explore the mechanisms of the growth and aroma-producing metabolism of Pichia anomala under ethanol stress,transcriptomic and metabolomic results were collected from different concentrations(3%,6%and 9%)of the ethanol stressor,and genes,metabolites and metabolic pathways that relate to growth and aroma-producing were screened.Integrated transcriptomic and metabolomic results showed that P.anomala could respond to ethanol stress by activating purine and pyrimidine,glycerophospholipid and antioxidant metabolic pathways.However,the damage to the growth of P.anomala under ethanol stress was closely related to the inhibition of carbohydrate metabolism,ABC transporter,energy metabolism and amino acid pathways,the influence on these pathways became more serious with the increase of ethanol concentrations.Meantime,the decrease in production of phenethyl alcohol and isoamyl alcohol was related to the significantly down-regulated of ARO9,ARO10,ADH1 and ADH2 genes expression in phenylalanine,tyrosine and tryptophan,and glycolysis pathways of P.anomala under ethanol stress.The enhanced expression of ATF1,EAT1,EEB1 and TGL2 genes in P.anomala was the main reason for the high yield of ethyl caproate and ethyl acetate under ethanol stress.These results revealed a theoretical basis for further study of the effect mechanisms of ethanol stress on P.anomala and molecular targets for the construction of genetic engineering strains with high ethanol tolerance and high aroma production.展开更多
Nineteen yeast strains were screened from the soil,dead branches,and fruit peels of a dragon fruit orchard.The yeast strain Z03M was obtained through preliminary screening,rescreening,and sensory flavor evaluation.Thi...Nineteen yeast strains were screened from the soil,dead branches,and fruit peels of a dragon fruit orchard.The yeast strain Z03M was obtained through preliminary screening,rescreening,and sensory flavor evaluation.This strain has certain alcohol-producing characteristics and good aroma-producing performance.Based on morphological and molecular identification,it was identified as Pichia kudriavzevii.The differences in flavor in dragon fruit wine from natural fermentation,inoculation with strain Z03M,commercial yeast,and mixed fermentation were comprehensive analyzed and compared via high-performance liquid chromatography,gas chromatography-mass spectrometry and gas chromatography-ion mobility spectroscopy.During the fermentation process of dragon fruit wine,We found that strain Z03M preferentially utilizes glucose.Malic acid and lactic acid are the main organic acids found in dragon fruit wine.The relative contents of volatile flavor compounds such as alcohols,aldehydes,terpenes,and heterocyclics of dragon fruit wine fermented with strain Z03M were 71.11%,4.34%,0.32%,and 1.78%,respectively,which were significantly higher than those of the other fermented samples.Among them,the content of 3-methyl-1-butanol was high,providing a banana aroma to the dragon fruit wine.Additionally,the wine fermented by a mixture of strain Z03M and commercial yeast had a high content of ester compounds,indicating that mixed fermentation can improve the flavor quality of dragon fruit wine.The results of this study have the potential value for the production of dragon fruit wine and for the research and development of dragon fruit products.展开更多
In Huangjiu(Chinese rice wine)production,the use of pure culture fermentation with Saccharomyces cerevisiae for alcoholic fermentation typically results in a product characterized by a singular flavor profile and limi...In Huangjiu(Chinese rice wine)production,the use of pure culture fermentation with Saccharomyces cerevisiae for alcoholic fermentation typically results in a product characterized by a singular flavor profile and limited diversity.This study isolated a Wickerhamomyces anomalus strain,JQY23,from Jiuqu,which demonstrates notable resistance to high sugar and alcohol concentrations,along with the ability to produce aromatic compounds.The strain was utilized in mixed culture fermentation with S.cerevisiae 724 during millet Huangjiu production to evaluate its impact on the flavor profile of the fermented samples.Analysis of sugar consumption rates,organic acids,and volatile flavor compounds-including esters,alcohols,and aldehydes-revealed that sequential inoculation of JQY23 followed by S.cerevisiae 724(JQY23-1d-Sc724)maintained a sugar consumption rate similar to that of fermentation with S.cerevisiae alone,while significantly increasing the levels of higher alcohols and acetate esters in the fermented liquor(p<0.05).Notably,this strategy addresses the issue of low fermentation efficiency associated with the W.anomalus strain in single-strain fermentation.Moreover,it promoted the production of esters,including ethyl caprate,ethyl hexanoate,and 2-ethylhexyl acetate.Through sequential inoculation(JQY23-1d-Sc724),the millet Huangjiu displays a well-balanced combination of moderate sweetness and acidity,complemented by a harmonious aroma,nuanced layers of flavor,and exceptional sensory qualities.This study explores the use of aroma-enhancing yeasts to enhance millet Huangjiu quality,fostering the development of diversified,customized Huangjiu products and bridging the gap between traditional methods and modern quality standards.展开更多
基金supported by the National Natural Science Foundation of China(No.31960474)Research Project of Liquor Making Biological Technology and Application Key Laboratory of Sichuan Province(NJ2022-02)Research Project of State Key Laboratory of Food Science and Technology(SKLF-ZZB-202116).
文摘Ethanol stress is an important environmental factor that affects physiological metabolism and aroma-producing capacity of yeast during the brewing process of alcoholic products.To explore the mechanisms of the growth and aroma-producing metabolism of Pichia anomala under ethanol stress,transcriptomic and metabolomic results were collected from different concentrations(3%,6%and 9%)of the ethanol stressor,and genes,metabolites and metabolic pathways that relate to growth and aroma-producing were screened.Integrated transcriptomic and metabolomic results showed that P.anomala could respond to ethanol stress by activating purine and pyrimidine,glycerophospholipid and antioxidant metabolic pathways.However,the damage to the growth of P.anomala under ethanol stress was closely related to the inhibition of carbohydrate metabolism,ABC transporter,energy metabolism and amino acid pathways,the influence on these pathways became more serious with the increase of ethanol concentrations.Meantime,the decrease in production of phenethyl alcohol and isoamyl alcohol was related to the significantly down-regulated of ARO9,ARO10,ADH1 and ADH2 genes expression in phenylalanine,tyrosine and tryptophan,and glycolysis pathways of P.anomala under ethanol stress.The enhanced expression of ATF1,EAT1,EEB1 and TGL2 genes in P.anomala was the main reason for the high yield of ethyl caproate and ethyl acetate under ethanol stress.These results revealed a theoretical basis for further study of the effect mechanisms of ethanol stress on P.anomala and molecular targets for the construction of genetic engineering strains with high ethanol tolerance and high aroma production.
基金supported by the Science and Technology Support Project of Guizhou Province,China([2020]1Y154),([2020]1Y116),([2021]General 273),([2021]General 121),and([2022]General 148)Guizhou University Laboratory Open Project(SYSKF2023-069).
文摘Nineteen yeast strains were screened from the soil,dead branches,and fruit peels of a dragon fruit orchard.The yeast strain Z03M was obtained through preliminary screening,rescreening,and sensory flavor evaluation.This strain has certain alcohol-producing characteristics and good aroma-producing performance.Based on morphological and molecular identification,it was identified as Pichia kudriavzevii.The differences in flavor in dragon fruit wine from natural fermentation,inoculation with strain Z03M,commercial yeast,and mixed fermentation were comprehensive analyzed and compared via high-performance liquid chromatography,gas chromatography-mass spectrometry and gas chromatography-ion mobility spectroscopy.During the fermentation process of dragon fruit wine,We found that strain Z03M preferentially utilizes glucose.Malic acid and lactic acid are the main organic acids found in dragon fruit wine.The relative contents of volatile flavor compounds such as alcohols,aldehydes,terpenes,and heterocyclics of dragon fruit wine fermented with strain Z03M were 71.11%,4.34%,0.32%,and 1.78%,respectively,which were significantly higher than those of the other fermented samples.Among them,the content of 3-methyl-1-butanol was high,providing a banana aroma to the dragon fruit wine.Additionally,the wine fermented by a mixture of strain Z03M and commercial yeast had a high content of ester compounds,indicating that mixed fermentation can improve the flavor quality of dragon fruit wine.The results of this study have the potential value for the production of dragon fruit wine and for the research and development of dragon fruit products.
基金supported by the Major Scientific and Technological Innovation Project of Shandong Province(No.2022TZXD0029)the Major Innovation Pilot Project of Integration of Science,Education and Industry of Qilu University of Technology(Shandong Academy of Science)[grant number 2022JBZ01-08].
文摘In Huangjiu(Chinese rice wine)production,the use of pure culture fermentation with Saccharomyces cerevisiae for alcoholic fermentation typically results in a product characterized by a singular flavor profile and limited diversity.This study isolated a Wickerhamomyces anomalus strain,JQY23,from Jiuqu,which demonstrates notable resistance to high sugar and alcohol concentrations,along with the ability to produce aromatic compounds.The strain was utilized in mixed culture fermentation with S.cerevisiae 724 during millet Huangjiu production to evaluate its impact on the flavor profile of the fermented samples.Analysis of sugar consumption rates,organic acids,and volatile flavor compounds-including esters,alcohols,and aldehydes-revealed that sequential inoculation of JQY23 followed by S.cerevisiae 724(JQY23-1d-Sc724)maintained a sugar consumption rate similar to that of fermentation with S.cerevisiae alone,while significantly increasing the levels of higher alcohols and acetate esters in the fermented liquor(p<0.05).Notably,this strategy addresses the issue of low fermentation efficiency associated with the W.anomalus strain in single-strain fermentation.Moreover,it promoted the production of esters,including ethyl caprate,ethyl hexanoate,and 2-ethylhexyl acetate.Through sequential inoculation(JQY23-1d-Sc724),the millet Huangjiu displays a well-balanced combination of moderate sweetness and acidity,complemented by a harmonious aroma,nuanced layers of flavor,and exceptional sensory qualities.This study explores the use of aroma-enhancing yeasts to enhance millet Huangjiu quality,fostering the development of diversified,customized Huangjiu products and bridging the gap between traditional methods and modern quality standards.
