The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Z...The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Zaopei,especially the metabolic function of rare taxa.Here,an experiment on industrial size was designed to assess the effects of 6 combinations(3 kinds of Daqu×2 kinds of PM)on the composition and assembly of different taxa,as well as the flavor profile.The results showed that Zaopei's microbiota was composed of a few abundant taxa and enormous rare taxa,and rare bacterial and abundant fungal subcommunities were significantly affected by combination patterns.The assembly processes of abundant/rare taxa and bacterial/fungal communities were distinct,and environmental changes mediated the balance between stochastic and deterministic processes in rare bacteria assembly.Furthermore,specific combination patterns improved the flavor quality of Zaopei by enhancing the interspecies interaction,which was closely related to rare taxa,especially rare bacteria.These findings highlighted that rare bacteria might be the keystone in involving community interaction and maintaining metabolic function,which provided a scientific foundation for better understanding and regulating the brewing microbiota from the viewpoint of microbial ecology.展开更多
采用Illumina Mi Seq高通量测序技术对不同发酵阶段低温大曲的真菌菌群多样性进行解析,探究低温大曲发酵过程中真菌群落结构的演替规律。结果表明,从入库前到拆曲,低温大曲中真菌菌群的超1指数和香农指数分别从156和2.90上升至376和4.29...采用Illumina Mi Seq高通量测序技术对不同发酵阶段低温大曲的真菌菌群多样性进行解析,探究低温大曲发酵过程中真菌群落结构的演替规律。结果表明,从入库前到拆曲,低温大曲中真菌菌群的超1指数和香农指数分别从156和2.90上升至376和4.29,均依次在上霉、起潮火和潮火阶段出现显著提升(P<0.05)。马氏距离聚类分析结果显示,在潮火阶段之前,各阶段的低温大曲真菌群落结构各不相同,而在潮火阶段之后,群落结构趋于稳定。低温大曲发酵过程中共注释到9个优势真菌属(平均相对丰度>1.0%),包括覆膜孢酵母菌属(Saccharomycopsis)、威克汉姆酵母菌属(Wickerhamomyces)、曲霉属(Aspergillus)等,入库前,以Wickerhamomyces和Saccharomycopsis为主;上霉后,以Saccharomycopsis和根霉菌属(Rhizopus)为主。整个发酵过程中的核心类群由Wickerhamomyces、Saccharomyces和汉逊酵母菌属(Hanseniaspora)等组成,而入库后的特有类群主要由Rhizopus和Saccharomycopsis等组成。由此可见,上霉、起潮火和潮火阶段对低温大曲中真菌丰富度和多样性的提升具有促进作用,且潮火阶段对大曲中真菌群落结构的稳定亦有着积极影响。展开更多
A yeast strain had been isolated by dilution-plate from the Daqu samples in our study. The strain was identified as a strain of Rhodotorula aurantiaca through observation of its morphological features, micromorphologi...A yeast strain had been isolated by dilution-plate from the Daqu samples in our study. The strain was identified as a strain of Rhodotorula aurantiaca through observation of its morphological features, micromorphological observation and biolog identification system.展开更多
Abstract： Daqu distiller＇s grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The singl...Abstract： Daqu distiller＇s grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The single factor tests were used to investigate the effects of ratio of strains, inoculum size, culture temperature and culture time on the production of microbial oils. The best processing conditions were obtained by orthogonal test through measuring the content of microbial oils in product. The result shows that the microbial oils content of the co-fermented product under the ratio of Trichoderma.koningii to Trichosporon cutaneum of 1：1, the inoculum size of strains of 11% at 28 ℃ for 6 d is 7.15 g/L. It is shown that the production of microbial oils co-fermented by Trichoderma.koningii and Trichosporon cutaneum with Daqu distiller＇s grains is possible. The research provides a new idea for the reuse of Daqu distiller＇s grains and also provides a new way for the development of microbial oils.展开更多
Daqu is the fermenting starter in Chinese Baijiu brewing,contributing functional microorganisms,enzymes and flavor substances to the grain fermentation.Traditional daqu is produced in open environment where environmen...Daqu is the fermenting starter in Chinese Baijiu brewing,contributing functional microorganisms,enzymes and flavor substances to the grain fermentation.Traditional daqu is produced in open environment where environmental factors and microbiota are critical to daqu and Baijiu quality.Mechanization is the direction of Baijiu production development.In this study,we investigated the mechanism of the effect of mechanized environment and manufacturing process on daqu production.Many functional microorganisms(e.g.Acetobacter,lactic acid bacteria and yeast)were distributed in the process environment,including indoor air,tube and equipment surfaces,which contributed to the initial bacterial/fungal composition in daqu(71.62%/28.47%)along with mature daqu powder(21.1%/61.65%).Our results also showed daqu microbiota formation was influenced by both stochastic and deterministic processes.The initial microorganisms produced large amounts of organic acids(19.24 g/kg)and bioheat(58.3◦C)during early fermentation stage,leading to a rapid temperature rise and water loss under the stacking process.Mature daqu powder mainly provided thermophilic microorganisms for fermentation stages during and after temperature rise,including Thermoactinomyces,Thermoascus,Thermomyces,Rhizomucor and Rhizopus,which produced enzymes and amino nitrogen for Baijiu fermentation,also ensuring stable microbiota among process batches.This work revealed the origin of the microbial community of strong-flavor daqu and showed that ecological environment suitable for daqu fermentation was created during the long-term continuous production process by adding mature daqu powder during daqu brick making and sprinkling it in the workshop,by which product quality was guaranteed.展开更多
High content of ethyl acetate may destroy the typical flavor of Chinese Nong-xiang Baijiu.Formation of ethyl acetate is closely related to its precursor acetic acid from Daqu starter in the fermentation process of Chi...High content of ethyl acetate may destroy the typical flavor of Chinese Nong-xiang Baijiu.Formation of ethyl acetate is closely related to its precursor acetic acid from Daqu starter in the fermentation process of Chinese Baijiu.In this study,the potential functional microbiota responsible for production of acetic acid was explored by correlation analysis and function prediction in Nong-xiang Daqu from different geographical regions.Our results revealed that the microbial community of Daqu starter was correlated with its acetic acid content.In addition,the relative abundances of Weissella,Lactobacillus,Bacillus,Kroppenstedtia,and Pichia were higher in the Daqu with high content of acetic acid.Furthermore,Acetobacter,Weissella,Lactobacillus,Pichia,Candida,and Rhizo-mucor were significantly(p<0.01)and positively correlated with acetic acid.Meanwhile,higher abundances of most genes that encoding enzymes participated in glycolysis and pentose phosphate pathways for acetic acid synthesis,were observed by PICRUSt2 approach in the Daqu starters with high content of acetic acid.Taken together,Acetobacter,Weissella,Lactobacillus,Pichia,and Candida were determined as the potential functional microbiota for producing acetic acid in Nong-xiang Daqu starters.These results provided evidence of microbiota for revealing the possible causes of high acetic acid and ethyl acetate in Nong-xiang Baijiu brewing process,and laid theoretical foundation for regulation of Baijiu fermentation by functional microbiota.展开更多
基金supported by the Cooperation Project of Luzhou Laojiao Co.,Ltd.Sichuan University (21H0997)。
文摘The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Zaopei,especially the metabolic function of rare taxa.Here,an experiment on industrial size was designed to assess the effects of 6 combinations(3 kinds of Daqu×2 kinds of PM)on the composition and assembly of different taxa,as well as the flavor profile.The results showed that Zaopei's microbiota was composed of a few abundant taxa and enormous rare taxa,and rare bacterial and abundant fungal subcommunities were significantly affected by combination patterns.The assembly processes of abundant/rare taxa and bacterial/fungal communities were distinct,and environmental changes mediated the balance between stochastic and deterministic processes in rare bacteria assembly.Furthermore,specific combination patterns improved the flavor quality of Zaopei by enhancing the interspecies interaction,which was closely related to rare taxa,especially rare bacteria.These findings highlighted that rare bacteria might be the keystone in involving community interaction and maintaining metabolic function,which provided a scientific foundation for better understanding and regulating the brewing microbiota from the viewpoint of microbial ecology.
文摘采用Illumina Mi Seq高通量测序技术对不同发酵阶段低温大曲的真菌菌群多样性进行解析,探究低温大曲发酵过程中真菌群落结构的演替规律。结果表明,从入库前到拆曲,低温大曲中真菌菌群的超1指数和香农指数分别从156和2.90上升至376和4.29,均依次在上霉、起潮火和潮火阶段出现显著提升(P<0.05)。马氏距离聚类分析结果显示,在潮火阶段之前,各阶段的低温大曲真菌群落结构各不相同,而在潮火阶段之后,群落结构趋于稳定。低温大曲发酵过程中共注释到9个优势真菌属(平均相对丰度>1.0%),包括覆膜孢酵母菌属(Saccharomycopsis)、威克汉姆酵母菌属(Wickerhamomyces)、曲霉属(Aspergillus)等,入库前,以Wickerhamomyces和Saccharomycopsis为主;上霉后,以Saccharomycopsis和根霉菌属(Rhizopus)为主。整个发酵过程中的核心类群由Wickerhamomyces、Saccharomyces和汉逊酵母菌属(Hanseniaspora)等组成,而入库后的特有类群主要由Rhizopus和Saccharomycopsis等组成。由此可见,上霉、起潮火和潮火阶段对低温大曲中真菌丰富度和多样性的提升具有促进作用,且潮火阶段对大曲中真菌群落结构的稳定亦有着积极影响。
文摘A yeast strain had been isolated by dilution-plate from the Daqu samples in our study. The strain was identified as a strain of Rhodotorula aurantiaca through observation of its morphological features, micromorphological observation and biolog identification system.
基金Project(10A110) supported by Hunan Provincial Education Department of ChinaProject(2010JT4055) supported by Hunan Provincial Science & Technology Department of China
文摘Abstract： Daqu distiller＇s grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The single factor tests were used to investigate the effects of ratio of strains, inoculum size, culture temperature and culture time on the production of microbial oils. The best processing conditions were obtained by orthogonal test through measuring the content of microbial oils in product. The result shows that the microbial oils content of the co-fermented product under the ratio of Trichoderma.koningii to Trichosporon cutaneum of 1：1, the inoculum size of strains of 11% at 28 ℃ for 6 d is 7.15 g/L. It is shown that the production of microbial oils co-fermented by Trichoderma.koningii and Trichosporon cutaneum with Daqu distiller＇s grains is possible. The research provides a new idea for the reuse of Daqu distiller＇s grains and also provides a new way for the development of microbial oils.
基金This work was financially supported by the National Natural Science Foundation of China(22138004)the first phase of the connotation construction of the 14th Five-Year Plan of Tibetan medicine(2021ZYYGH008)Sichuan post-doctoral program.
文摘Daqu is the fermenting starter in Chinese Baijiu brewing,contributing functional microorganisms,enzymes and flavor substances to the grain fermentation.Traditional daqu is produced in open environment where environmental factors and microbiota are critical to daqu and Baijiu quality.Mechanization is the direction of Baijiu production development.In this study,we investigated the mechanism of the effect of mechanized environment and manufacturing process on daqu production.Many functional microorganisms(e.g.Acetobacter,lactic acid bacteria and yeast)were distributed in the process environment,including indoor air,tube and equipment surfaces,which contributed to the initial bacterial/fungal composition in daqu(71.62%/28.47%)along with mature daqu powder(21.1%/61.65%).Our results also showed daqu microbiota formation was influenced by both stochastic and deterministic processes.The initial microorganisms produced large amounts of organic acids(19.24 g/kg)and bioheat(58.3◦C)during early fermentation stage,leading to a rapid temperature rise and water loss under the stacking process.Mature daqu powder mainly provided thermophilic microorganisms for fermentation stages during and after temperature rise,including Thermoactinomyces,Thermoascus,Thermomyces,Rhizomucor and Rhizopus,which produced enzymes and amino nitrogen for Baijiu fermentation,also ensuring stable microbiota among process batches.This work revealed the origin of the microbial community of strong-flavor daqu and showed that ecological environment suitable for daqu fermentation was created during the long-term continuous production process by adding mature daqu powder during daqu brick making and sprinkling it in the workshop,by which product quality was guaranteed.
基金funded by the Sichuan Province Key Research and Development Project(2021YFS0340)Doctoral Scientific Fund Project of Southwest University of Science and Technology(20zx7130)Open Fund of Key Laboratory in Luzhou(NJ202201)。
文摘High content of ethyl acetate may destroy the typical flavor of Chinese Nong-xiang Baijiu.Formation of ethyl acetate is closely related to its precursor acetic acid from Daqu starter in the fermentation process of Chinese Baijiu.In this study,the potential functional microbiota responsible for production of acetic acid was explored by correlation analysis and function prediction in Nong-xiang Daqu from different geographical regions.Our results revealed that the microbial community of Daqu starter was correlated with its acetic acid content.In addition,the relative abundances of Weissella,Lactobacillus,Bacillus,Kroppenstedtia,and Pichia were higher in the Daqu with high content of acetic acid.Furthermore,Acetobacter,Weissella,Lactobacillus,Pichia,Candida,and Rhizo-mucor were significantly(p<0.01)and positively correlated with acetic acid.Meanwhile,higher abundances of most genes that encoding enzymes participated in glycolysis and pentose phosphate pathways for acetic acid synthesis,were observed by PICRUSt2 approach in the Daqu starters with high content of acetic acid.Taken together,Acetobacter,Weissella,Lactobacillus,Pichia,and Candida were determined as the potential functional microbiota for producing acetic acid in Nong-xiang Daqu starters.These results provided evidence of microbiota for revealing the possible causes of high acetic acid and ethyl acetate in Nong-xiang Baijiu brewing process,and laid theoretical foundation for regulation of Baijiu fermentation by functional microbiota.
