Alternaria alternata is a prevalent pathogenic fungus that infects a wide variety of fruits and vegetables,resulting in substantial economic losses.Microbial volatile organic compounds(mVOCs)serve as effective biofumi...Alternaria alternata is a prevalent pathogenic fungus that infects a wide variety of fruits and vegetables,resulting in substantial economic losses.Microbial volatile organic compounds(mVOCs)serve as effective biofumigants for the control of fungal infestations.In this study,we evaluated the inhibitory activity of volatile compounds produced(VOCs)emitted by Saccharomycopsis fibuligera KN-1 against A.alternata,demonstrating its capability to effectively inhibit mycelial growth and retard spore germination.Headspace solid-phase microextraction-gas chromatography/mass spectrometry(HS-SPME-GC/MS)was used to identify 23 volatile organic compounds,mainly including alcohols,acids,esters,phenols,ethers and alkanes.Among them,2-methylbutyric acid plays an important role in the antifungal effect.Phenylethanol and 3-methyl-1-butanol also demonstrated strong inhibitory effects.Notably,combining the IC_(50) values of ethyl octanoate and 2-methylbutyric acid resulted in significant synergistic effects.Furthermore,SEM analysis revealed that the abnormal morphology of A.alternata mycelium was observed after fumigation.In addition,the cell membrane may be a legitimate target of the VOCs by S.fibuligera KN-1.Transcriptomic and proteomic analyses indicated that S.fibuligera KN-1 disrupts the interconversion of pentose and gluconate,oxidative phosphorylation,and ABC transporters.This disruption impairs ATP production and carbon utilization,resulting in mitochondrial damage,decreased stress resistance,suggesting potential mechanistic interconnections.Consequently,S.fibuligera KN-1 emerges as a promising antifungal agent A.alternata infections.展开更多
Our previous research found that farnesol,a fungal quorum-sensing molecule,may simultaneously regulate the yeast-to-hypha transition and promote squalene biosynthesis in Saccharomycopsis fibuligera.To confirm this,in ...Our previous research found that farnesol,a fungal quorum-sensing molecule,may simultaneously regulate the yeast-to-hypha transition and promote squalene biosynthesis in Saccharomycopsis fibuligera.To confirm this,in this study,we conducted farnesol exposure experiments and analyzed the changes in morphology and squalene content of S.fibuligera.The structure and function of S.fibuligera squalene synthase(SfSQS)were analyzed using molecular docking simulations and protein expression.Metabolomics and tandem mass tag(TMT)-labeling proteomics were employed to investigate the mechanisms underlying farnesol-induced morphogenesis and metabolic changes in S.fibuligera.The results showed that treatments with 50μmol/L and 100μmol/L farnesol significantly increased squalene content by over 1.67-fold in S.fibuligera.High concentrations of farnesol promoted hyphal elongation while suppressing yeast-form cell growth in S.fibuligera.Analysis of SfSQS demonstrated that it forms stable binding complexes with farnesyl pyrophosphate(FPP)and presqualene diphosphate and exhibits catalytic activity in converting FPP to squalene.Metabolomic and proteomic analyses revealed that farnesol enhances squalene biosynthesis and regulates sterol metabolism by modulating the mevalonate pathway in S.fibuligera.Furthermore,the morphologic changes in S.fibuligera are linked to the regulation of its response to farnesol-induced stresses,including oxidative stress and DNA replication stress.This research advances our understanding of quorum sensing in dimorphic yeasts and provides a theoretical basis for yeast-based squalene production.展开更多
Saccharomycopsis fibuligera is a key microorganism in Hakka huangjiu jiuyao,but its flavor contribution remains unclear.In this study,a high-amylase-producing strain,S.fibuligera SF2312,was isolated from traditional j...Saccharomycopsis fibuligera is a key microorganism in Hakka huangjiu jiuyao,but its flavor contribution remains unclear.In this study,a high-amylase-producing strain,S.fibuligera SF2312,was isolated from traditional jiuyao.This strain exhibits broad substrate utilization and strong tolerance to fermentation-related stresses.A monomicrobial jiuyao was developed from it,with saccharifying and liquefying activities optimized through singlefactor and response-surface methodology,reaching 282.69±3.01 U/g and 0.3092±0.0034 U/g,increases of 33.94% and 57.69%.Huangjiu fermented with this jiuyao met expected physicochemical standards.Flavor analysis by HPLC and GC-MS showed that co-inoculation of the mono-microbial jiuyao with traditional jiuqu produced the strongest overall aroma enhancement,increasing total volatile compounds 2.38-fold and signifi-cantly raising phenylethanol and ethyl acetate levels by 113.56% and 108.83%.When the mono-microbial jiuyao was used alone,total volatiles still increased 1.57-fold,with phenylethanol and ethyl acetate rising 15.92% and 223.27%,highlighting the ester-producing characteristics of S.fibuligera in the absence of competing microbes.These results indicate that mono-microbial jiuyao based on S.fibuligera can significantly enhance the aroma profile of Hakka huangjiu,and that the extent of this enhancement is influenced by interactions within the microbial community.This provides new scientific guidance for targeted improvement of fermentation starters and flavor quality in traditional Chinese huangjiu.展开更多
In this study,Saccharomycopsis fibuligera FBKL2.8DCJS1 and Lacticaseibacillus paracasei FBKL1.3028 were jointly introduced into Dendrobium officinale liquid to probe alterations in their active constituents.Over a 15-...In this study,Saccharomycopsis fibuligera FBKL2.8DCJS1 and Lacticaseibacillus paracasei FBKL1.3028 were jointly introduced into Dendrobium officinale liquid to probe alterations in their active constituents.Over a 15-day fermentation period,analyses were conducted to ascertain shifts in physicochemical attributes,antioxidant capacity,metabolite transformation,flavor profiles,and sensory characteristics.The findings revealed augmented color differentiation,increased antioxidant potential,and heightened acidity post-fermentation.This finding points to a positive correlation between acidity and color variation and antioxidant capacity.The microbial fermentation process was advantageous for ameliorating both the color and taste of D.officinale while also bolstering its antioxidant capacity.Additionally,several bioactive substances favorable to the organism,including metabolites such as proscillaridin,D-sorbitol,and glucomannan,were found to be upregulated postfermentation.The most enriched metabolic pathways identified in the KEGG metabolic pathway were purine metabolism and amino acid metabolism.Notably,co-cultivating S.fibuligera and L.paracasei amplified the production of ethyl lactate,indicating that this co-culture approach induced higher levels of this compound.Consequently,fermenting D.officinale with S.fibuligera and L.paracasei not only enhanced its bioactive properties but also enhanced its flavor profile.展开更多
To unravel the mechanism underlying the dimorphic formation of Saccharomycopsis fibuligera during dough fermentation,we assembled a high-quality chromosome-scale genome and conducted comparative genomic analysis.Furth...To unravel the mechanism underlying the dimorphic formation of Saccharomycopsis fibuligera during dough fermentation,we assembled a high-quality chromosome-scale genome and conducted comparative genomic analysis.Furthermore,we examined the differences between the yeast-like cells and hyphae at both transcriptome and metabolome levels.The completed S.fibuligera ACX0001 genome of 19.29 Mb comprised seven chromosomes and contained 6115 predicted protein-coding genes.Comparative genomic analysis revealed that S.fibuligera possessed 51 unique gene families comprising 85 annotated genes.The advantageous genes related to carbon metabolism pathway were accumulated in S.fibuligera during evolution,including the unique genes encoding glycosyl hydrolases such as glucan endo-1,3-βglucosidase,which distinguished it from the other yeasts.Transcriptomic and metabolomic analysis identified 568 differentially expressed genes and 109 differentially abundant metabolites between the yeast-like cells and hyphae,respectively.In response to the dough environment,S.fibuligera activated the expression of the glucan endo-1,3-βglucosidase,which can soften the cell wall and promote germination of yeast-like cells.Simultaneously,the flux of acetyl-CoA was redirected towards fatty acid and steroid biosynthesis in S.fibuligera,which influenced the production of quorum-sensing molecules,thereby contributing to the dimorphic transition.Therefore,the dimorphic growth of S.fibuligera was collectively governed by the glycosyl hydrolase family genes,central carbon metabolism,and quorum-sensing molecules.This study provides a theoretical foundation for the potential application of S.fibuligera in food industry.展开更多
Saccharomycopsis ferment filtrate (SFF), mainly used in skin care products, has been reported to inhibit inflammatory nitric oxide production and prevent epidermal damage. However, the effects of SFF on epidermal kera...Saccharomycopsis ferment filtrate (SFF), mainly used in skin care products, has been reported to inhibit inflammatory nitric oxide production and prevent epidermal damage. However, the effects of SFF on epidermal keratinocytes have not yet been explored. We investigated the effects of SFF on skin barrier function using human primary epidermal keratinocytes. Cell viability was determined by MTT assay. The mRNA and protein expression levels of tight junction proteins (claudin-1, -3, -4, occludin, ZO-1) were analyzed by RT-PCR and Western blotting, respectively. The effect of SFF on the barrier formation of epidermal keratinocytes was measured by transepithelial electrical resistance (TER). Rescue of cell death from H2O2 treatment was evaluated by annexin V staining. SFF, at concentrations that did not cause significant change of cell viability, induced dose-dependent cell-cell adhesion and formation of an organized monolayer structure. Pretreatment of keratinocytes with EGTA, a Ca2+ chelator, did not inhibit the cell-cell adhesion of keratinocytes by SFF, indicating a Ca2+-independent mechanism. The mRNA and protein levels of claudin-1 in keratinocytes were up-regulated by SFF treatment in a dose-dependent manner. The expressions of other tight junctions (TJs) including claudin-3 & 4, occludin and ZO-1 were also similarly increased in SFF-treated epidermal keratinocytes. The promoting effect of SFF on the barrier function of epidermal keratinocytes was further confirmed by the increased TER value in SFF-treated epidermal keratinocytes. Annexin V staining confirmed that SFF markedly decreased the number of dead cells resulted from H2O2 injury. Taken together, our results provided the first evidence that SFF enhanced keratinocytes barrier function by increasing the expression of TJs and TER.展开更多
The microbial ecosystems involved in traditional food fermentation are often complex and unpredictable,posing significant challenges for quality assurance.Sauce-flavor baijiu(SFB)fermentation exemplifies a complex sol...The microbial ecosystems involved in traditional food fermentation are often complex and unpredictable,posing significant challenges for quality assurance.Sauce-flavor baijiu(SFB)fermentation exemplifies a complex solid-state process.This study investigated a bioaugmentation strategy employing two osmotolerant yeasts,Saccha-romycopsis fibuligera Y30 and Clavispora lusitaniae F13008,not only for their direct metabolic role but also for their ability to influence the broader ecological microbial community.High-throughput sequencing revealed that the inoculation significantly restructured microbial succession.The final community exhibited a unique domi-nance profile,with Saccharomyces constituting up to 69.41%of the fungal community and Lactobacillus reaching 67.21%in the bacterial community.This altered consortium enhanced substrate utilization,resulting in a 17%increase in starch breakdown and a 20%increase in total acidity compared to the control at a 30-day fermen-tation period.Metabolomic analysis indicated a substantial increase in flavor complexity,with an increase of 38.7%to 42.3%in Y30 and F13008 groups,respectively,compared to the control.Key esters,such as ethyl acetate and ethyl caproate,and alcohol like phenylethyl alcohol,were found at significantly higher concentra-tions.Integrated network analysis revealed a strong association between the engineered microbial consortia and the production of these vital flavor compounds.Our findings suggest that targeted yeast inoculation acts as a significant ecological catalyst,orchestrating extensive metabolic changes to enhance both fermentation effi-ciency and sensory quality.This strategy presents a generalizable framework for managing the microbiology of various traditional fermented foods beyond baijiu.展开更多
This study aimed to isolate and characterize cellulase-producing yeasts from six traditional fermented foods and evaluate their potential for modifying wheat bran through solid-state fermentation.A total of 28 isolate...This study aimed to isolate and characterize cellulase-producing yeasts from six traditional fermented foods and evaluate their potential for modifying wheat bran through solid-state fermentation.A total of 28 isolates were obtained,from which five strains(SD-ZZ-3,HQ-CC-7,MQ-GZ-4,FT-XJ-1,and MQ-GZ-3)with high enzymatic index values were identified.Among the selected isolates,FT-XJ-1 strain displayed robust growth,the widest carbon utilization capacity and the highest cellulase activity in liquid culture.Moreover,the solid-state fermentation using each of the isolate inoculum induced significant changes in composition and structure of wheat bran,with noted reductions in insoluble dietary fiber and cellulose content.In particular,the bran sample fermented by FT-XJ-1 strain achieved the greatest cellulose reduction(28.57%)and decreased crystallinity of cellulose,illustrating the outperformed modification effect on wheat bran.With whole genome sequencing for FT-XJ-1,genes encoding cellulolytic enzymes were annotated,further validating the cellulase degradation capacities.Collectively,strain FT-XJ-1 could effectively degrade cellulose and improve wheat bran structure,which can be potentially used as promising starter for whole wheat product processing.展开更多
To acquire candidate non-Saccharomyces strains for preparation of high-quality Vidal icewine,11 representative indigenous non-Saccharomyces strains were selected for analyzing their production of organic acids,phenoli...To acquire candidate non-Saccharomyces strains for preparation of high-quality Vidal icewine,11 representative indigenous non-Saccharomyces strains were selected for analyzing their production of organic acids,phenolic compounds,aroma-active compounds and evaluating their sensory profile in Vidal juice.The results showed that the contents of organic acids in the wines were controlled and balanced well by the non-Saccharomyces strains as well as polyphenol concentrations were well improved during the fermentation.The strains differed from each other in their ability to produce aroma compounds,causing diversity and complexity of aroma characteristics in wine.Fermentation by Saccharomycopsis crataegensis YC30(Sc)and Hanseniaspora uvarum QTX22(Hu)could enhance the sweet and floral notes in Vidal icewine,especially Sc,which has never been reported before.It can not only enrich the aroma categories,but also increase the content ofδ-decalactone,γ-decalactone,ethyl isobutyrate,ethyl butyrate,phenethyl acetic acid,etc.The evaluation and optimization of non-Saccharomyces yeast strains could provide theoretical basis for the improvement of ice wine quality,and supply new ideas and strategies for the brewing of ice wine.展开更多
基金supported by Shandong Province Key R&D Plan(Rural Revitalization Science and Technology Innovation Boosting Action Plan)Project(2024TZXD012,2023TZXD056)2021 Taishan Industry Leading Talent Project(tscx202211079)the special Funds of the Central Government Guiding Local Science and Technology Development(YDZX2023098).
文摘Alternaria alternata is a prevalent pathogenic fungus that infects a wide variety of fruits and vegetables,resulting in substantial economic losses.Microbial volatile organic compounds(mVOCs)serve as effective biofumigants for the control of fungal infestations.In this study,we evaluated the inhibitory activity of volatile compounds produced(VOCs)emitted by Saccharomycopsis fibuligera KN-1 against A.alternata,demonstrating its capability to effectively inhibit mycelial growth and retard spore germination.Headspace solid-phase microextraction-gas chromatography/mass spectrometry(HS-SPME-GC/MS)was used to identify 23 volatile organic compounds,mainly including alcohols,acids,esters,phenols,ethers and alkanes.Among them,2-methylbutyric acid plays an important role in the antifungal effect.Phenylethanol and 3-methyl-1-butanol also demonstrated strong inhibitory effects.Notably,combining the IC_(50) values of ethyl octanoate and 2-methylbutyric acid resulted in significant synergistic effects.Furthermore,SEM analysis revealed that the abnormal morphology of A.alternata mycelium was observed after fumigation.In addition,the cell membrane may be a legitimate target of the VOCs by S.fibuligera KN-1.Transcriptomic and proteomic analyses indicated that S.fibuligera KN-1 disrupts the interconversion of pentose and gluconate,oxidative phosphorylation,and ABC transporters.This disruption impairs ATP production and carbon utilization,resulting in mitochondrial damage,decreased stress resistance,suggesting potential mechanistic interconnections.Consequently,S.fibuligera KN-1 emerges as a promising antifungal agent A.alternata infections.
基金supported by the National Natural Science Foundation of China(32072154)Henan Province Science and Technology Tackling Program(232102111073)the Henan Provincial Association for Science and Technology Talent Support Program(2023HYTP029).
文摘Our previous research found that farnesol,a fungal quorum-sensing molecule,may simultaneously regulate the yeast-to-hypha transition and promote squalene biosynthesis in Saccharomycopsis fibuligera.To confirm this,in this study,we conducted farnesol exposure experiments and analyzed the changes in morphology and squalene content of S.fibuligera.The structure and function of S.fibuligera squalene synthase(SfSQS)were analyzed using molecular docking simulations and protein expression.Metabolomics and tandem mass tag(TMT)-labeling proteomics were employed to investigate the mechanisms underlying farnesol-induced morphogenesis and metabolic changes in S.fibuligera.The results showed that treatments with 50μmol/L and 100μmol/L farnesol significantly increased squalene content by over 1.67-fold in S.fibuligera.High concentrations of farnesol promoted hyphal elongation while suppressing yeast-form cell growth in S.fibuligera.Analysis of SfSQS demonstrated that it forms stable binding complexes with farnesyl pyrophosphate(FPP)and presqualene diphosphate and exhibits catalytic activity in converting FPP to squalene.Metabolomic and proteomic analyses revealed that farnesol enhances squalene biosynthesis and regulates sterol metabolism by modulating the mevalonate pathway in S.fibuligera.Furthermore,the morphologic changes in S.fibuligera are linked to the regulation of its response to farnesol-induced stresses,including oxidative stress and DNA replication stress.This research advances our understanding of quorum sensing in dimorphic yeasts and provides a theoretical basis for yeast-based squalene production.
基金supported by the National Natural Science Foundation of China(Grant No.32302029)the Research Initiation Program(060302042313)of Guangdong Ocean UniversityStudent Innovation and Entrepreneurship Training Program Project(CXXL2024023)of Guangdong Ocean University.
文摘Saccharomycopsis fibuligera is a key microorganism in Hakka huangjiu jiuyao,but its flavor contribution remains unclear.In this study,a high-amylase-producing strain,S.fibuligera SF2312,was isolated from traditional jiuyao.This strain exhibits broad substrate utilization and strong tolerance to fermentation-related stresses.A monomicrobial jiuyao was developed from it,with saccharifying and liquefying activities optimized through singlefactor and response-surface methodology,reaching 282.69±3.01 U/g and 0.3092±0.0034 U/g,increases of 33.94% and 57.69%.Huangjiu fermented with this jiuyao met expected physicochemical standards.Flavor analysis by HPLC and GC-MS showed that co-inoculation of the mono-microbial jiuyao with traditional jiuqu produced the strongest overall aroma enhancement,increasing total volatile compounds 2.38-fold and signifi-cantly raising phenylethanol and ethyl acetate levels by 113.56% and 108.83%.When the mono-microbial jiuyao was used alone,total volatiles still increased 1.57-fold,with phenylethanol and ethyl acetate rising 15.92% and 223.27%,highlighting the ester-producing characteristics of S.fibuligera in the absence of competing microbes.These results indicate that mono-microbial jiuyao based on S.fibuligera can significantly enhance the aroma profile of Hakka huangjiu,and that the extent of this enhancement is influenced by interactions within the microbial community.This provides new scientific guidance for targeted improvement of fermentation starters and flavor quality in traditional Chinese huangjiu.
基金supported by the Youth Science and Technology Talents Development Project of Colleges and Universities of Guizhou Province(grant number:KY[2022]147)National Natural Science Foundation of China(grant number:32060518)+3 种基金R&D Contract for the Development of Huangjing and Dendrobium Health Food Series Products(K22-0115-001)Talent Base of Fermentation Engineering and Liquor Making in Guizhou Province([2018]3)Intelligent Brewing Platform for High-Quality Sauce-Flavoured White Wine(Qianke He Achievement[2022]Key 002)Construction of Guizhou Gaozhi Weixin Biotechnology Innovation and R&D Base(Qianke Zhongdian Cited Land[2022]4020).
文摘In this study,Saccharomycopsis fibuligera FBKL2.8DCJS1 and Lacticaseibacillus paracasei FBKL1.3028 were jointly introduced into Dendrobium officinale liquid to probe alterations in their active constituents.Over a 15-day fermentation period,analyses were conducted to ascertain shifts in physicochemical attributes,antioxidant capacity,metabolite transformation,flavor profiles,and sensory characteristics.The findings revealed augmented color differentiation,increased antioxidant potential,and heightened acidity post-fermentation.This finding points to a positive correlation between acidity and color variation and antioxidant capacity.The microbial fermentation process was advantageous for ameliorating both the color and taste of D.officinale while also bolstering its antioxidant capacity.Additionally,several bioactive substances favorable to the organism,including metabolites such as proscillaridin,D-sorbitol,and glucomannan,were found to be upregulated postfermentation.The most enriched metabolic pathways identified in the KEGG metabolic pathway were purine metabolism and amino acid metabolism.Notably,co-cultivating S.fibuligera and L.paracasei amplified the production of ethyl lactate,indicating that this co-culture approach induced higher levels of this compound.Consequently,fermenting D.officinale with S.fibuligera and L.paracasei not only enhanced its bioactive properties but also enhanced its flavor profile.
基金supported by the National Natural Science Foundation of China(32072154)Henan Province Science and Technology Tackling Program(232102111073)the Henan Provincial Association for Science and Technology Talent Support Program(2023HYTP029).
文摘To unravel the mechanism underlying the dimorphic formation of Saccharomycopsis fibuligera during dough fermentation,we assembled a high-quality chromosome-scale genome and conducted comparative genomic analysis.Furthermore,we examined the differences between the yeast-like cells and hyphae at both transcriptome and metabolome levels.The completed S.fibuligera ACX0001 genome of 19.29 Mb comprised seven chromosomes and contained 6115 predicted protein-coding genes.Comparative genomic analysis revealed that S.fibuligera possessed 51 unique gene families comprising 85 annotated genes.The advantageous genes related to carbon metabolism pathway were accumulated in S.fibuligera during evolution,including the unique genes encoding glycosyl hydrolases such as glucan endo-1,3-βglucosidase,which distinguished it from the other yeasts.Transcriptomic and metabolomic analysis identified 568 differentially expressed genes and 109 differentially abundant metabolites between the yeast-like cells and hyphae,respectively.In response to the dough environment,S.fibuligera activated the expression of the glucan endo-1,3-βglucosidase,which can soften the cell wall and promote germination of yeast-like cells.Simultaneously,the flux of acetyl-CoA was redirected towards fatty acid and steroid biosynthesis in S.fibuligera,which influenced the production of quorum-sensing molecules,thereby contributing to the dimorphic transition.Therefore,the dimorphic growth of S.fibuligera was collectively governed by the glycosyl hydrolase family genes,central carbon metabolism,and quorum-sensing molecules.This study provides a theoretical foundation for the potential application of S.fibuligera in food industry.
文摘Saccharomycopsis ferment filtrate (SFF), mainly used in skin care products, has been reported to inhibit inflammatory nitric oxide production and prevent epidermal damage. However, the effects of SFF on epidermal keratinocytes have not yet been explored. We investigated the effects of SFF on skin barrier function using human primary epidermal keratinocytes. Cell viability was determined by MTT assay. The mRNA and protein expression levels of tight junction proteins (claudin-1, -3, -4, occludin, ZO-1) were analyzed by RT-PCR and Western blotting, respectively. The effect of SFF on the barrier formation of epidermal keratinocytes was measured by transepithelial electrical resistance (TER). Rescue of cell death from H2O2 treatment was evaluated by annexin V staining. SFF, at concentrations that did not cause significant change of cell viability, induced dose-dependent cell-cell adhesion and formation of an organized monolayer structure. Pretreatment of keratinocytes with EGTA, a Ca2+ chelator, did not inhibit the cell-cell adhesion of keratinocytes by SFF, indicating a Ca2+-independent mechanism. The mRNA and protein levels of claudin-1 in keratinocytes were up-regulated by SFF treatment in a dose-dependent manner. The expressions of other tight junctions (TJs) including claudin-3 & 4, occludin and ZO-1 were also similarly increased in SFF-treated epidermal keratinocytes. The promoting effect of SFF on the barrier function of epidermal keratinocytes was further confirmed by the increased TER value in SFF-treated epidermal keratinocytes. Annexin V staining confirmed that SFF markedly decreased the number of dead cells resulted from H2O2 injury. Taken together, our results provided the first evidence that SFF enhanced keratinocytes barrier function by increasing the expression of TJs and TER.
基金supported by the National Natural Science Foundation of China(No.31830069 and 32001638)the Beijing Municipal Natural Science Foundation in conjunction with the Beijing Municipal Education Commission(No.KZ202110011016).
文摘The microbial ecosystems involved in traditional food fermentation are often complex and unpredictable,posing significant challenges for quality assurance.Sauce-flavor baijiu(SFB)fermentation exemplifies a complex solid-state process.This study investigated a bioaugmentation strategy employing two osmotolerant yeasts,Saccha-romycopsis fibuligera Y30 and Clavispora lusitaniae F13008,not only for their direct metabolic role but also for their ability to influence the broader ecological microbial community.High-throughput sequencing revealed that the inoculation significantly restructured microbial succession.The final community exhibited a unique domi-nance profile,with Saccharomyces constituting up to 69.41%of the fungal community and Lactobacillus reaching 67.21%in the bacterial community.This altered consortium enhanced substrate utilization,resulting in a 17%increase in starch breakdown and a 20%increase in total acidity compared to the control at a 30-day fermen-tation period.Metabolomic analysis indicated a substantial increase in flavor complexity,with an increase of 38.7%to 42.3%in Y30 and F13008 groups,respectively,compared to the control.Key esters,such as ethyl acetate and ethyl caproate,and alcohol like phenylethyl alcohol,were found at significantly higher concentra-tions.Integrated network analysis revealed a strong association between the engineered microbial consortia and the production of these vital flavor compounds.Our findings suggest that targeted yeast inoculation acts as a significant ecological catalyst,orchestrating extensive metabolic changes to enhance both fermentation effi-ciency and sensory quality.This strategy presents a generalizable framework for managing the microbiology of various traditional fermented foods beyond baijiu.
基金financial support by National Natural Science Foundation of China(32330081,32302136)additionally funded by R&D Program of Beijing Municipal Education Commission(KM202310011011).
文摘This study aimed to isolate and characterize cellulase-producing yeasts from six traditional fermented foods and evaluate their potential for modifying wheat bran through solid-state fermentation.A total of 28 isolates were obtained,from which five strains(SD-ZZ-3,HQ-CC-7,MQ-GZ-4,FT-XJ-1,and MQ-GZ-3)with high enzymatic index values were identified.Among the selected isolates,FT-XJ-1 strain displayed robust growth,the widest carbon utilization capacity and the highest cellulase activity in liquid culture.Moreover,the solid-state fermentation using each of the isolate inoculum induced significant changes in composition and structure of wheat bran,with noted reductions in insoluble dietary fiber and cellulose content.In particular,the bran sample fermented by FT-XJ-1 strain achieved the greatest cellulose reduction(28.57%)and decreased crystallinity of cellulose,illustrating the outperformed modification effect on wheat bran.With whole genome sequencing for FT-XJ-1,genes encoding cellulolytic enzymes were annotated,further validating the cellulase degradation capacities.Collectively,strain FT-XJ-1 could effectively degrade cellulose and improve wheat bran structure,which can be potentially used as promising starter for whole wheat product processing.
基金This research was supported by the Science and Technology Plan Project of Shaanxi(No.K3310218103 and K3010220051)the Science and Technology Innovation Project of Ningxia Agriculture and Forestry Academy(No.NKYJ-20-01 and NGSB-2021-5-04)Ningxia Youth Science and Technology Talent Project(No.NXKJTJGC2020140).
文摘To acquire candidate non-Saccharomyces strains for preparation of high-quality Vidal icewine,11 representative indigenous non-Saccharomyces strains were selected for analyzing their production of organic acids,phenolic compounds,aroma-active compounds and evaluating their sensory profile in Vidal juice.The results showed that the contents of organic acids in the wines were controlled and balanced well by the non-Saccharomyces strains as well as polyphenol concentrations were well improved during the fermentation.The strains differed from each other in their ability to produce aroma compounds,causing diversity and complexity of aroma characteristics in wine.Fermentation by Saccharomycopsis crataegensis YC30(Sc)and Hanseniaspora uvarum QTX22(Hu)could enhance the sweet and floral notes in Vidal icewine,especially Sc,which has never been reported before.It can not only enrich the aroma categories,but also increase the content ofδ-decalactone,γ-decalactone,ethyl isobutyrate,ethyl butyrate,phenethyl acetic acid,etc.The evaluation and optimization of non-Saccharomyces yeast strains could provide theoretical basis for the improvement of ice wine quality,and supply new ideas and strategies for the brewing of ice wine.
