Pomegranate residues(PRs),namely pomegranate peels and seeds remaining after juice extraction,constitute a significant agro-industrial residue in Greece.Despite their ample content in carbon sources and bioactive comp...Pomegranate residues(PRs),namely pomegranate peels and seeds remaining after juice extraction,constitute a significant agro-industrial residue in Greece.Despite their ample content in carbon sources and bioactive compounds,PRs are largely unexploited,with their management being an increasing concern for the pome-granate processing industry.The objective of this study was the development and characterization of a bio-process aiming at the biotechnological valorization of PRs for ethanol production.Specifically,a stepwise investigation was conducted,including(i)the production and chemical characterization of extracts/hydrolysates from PRs using distinct pretreatments not involving organic solvents or enzymatic hydrolysis;(ii)the assessment of the exploitability of a selected hydrolysate as fermentation feedstock using Saccharomyces cerevisiae;and(iii)the advancement of the bioprocess through the joined utilization in the fermentation substrate of PRs and seeded raisins(SRs),another important agro-industrial residue in Greece.The finally developed substrate,comprising a mixture of PRs/SRs extracts at concentrations 60/40%v/v,was used in three fermentation trials,and the fermentation process was quantitatively described using the Aiba model.The developed bioprocess resulted in satisfactorily high bioethanol production with the maximum attained concentration being 50.0±0.6 g/L.The maximum specific growth rate(μ_(max))of S.cerevisiae was estimated to be 0.1351/h and the bioethanol yield(Y_(ps)),namely the amount of produced ethanol/amount of consumed reducing sugars,was estimated to be 0.423 g/g.Hence,PRs can be efficiently used in the development of a fermentation substrate for bioethanol production,providing an economic and environmentally sustainable alternative to conventional feedstocks.展开更多
This article investigates the effects of nitric oxide （NO） on alcoholic fermentation and the qualities of Chinese Winter Jujube during storage, and explores the action mechanisms of browning and softening of fruits ...This article investigates the effects of nitric oxide （NO） on alcoholic fermentation and the qualities of Chinese Winter Jujube during storage, and explores the action mechanisms of browning and softening of fruits to provide theoretical proofs for using NO in the storage of Chinese Winter Jujube. Chinese Winter Jujube fruits were fumigated with different concentrations of NO gas （0, 10, 20, 30 μL L^-1） under anaerobic conditions and stored at 22±1℃ and 4± 1℃. The changes in appearance qualities, the contents of pyruvate, ethanol, acetaldehyde, and the activities of alcohol dehydrogenase （ADH） and lactate dehydrogenase （LDH） were investigated. The contents of pyruvate, ethanol, and acetaldehyde were significantly reduced, and the peak of pyruvate content was delayed by 20 μL L^-1 NO. The activities of ADH and LDH in 20 μL L^-1 NO treated fruits were also significantly inhibited. However, the alcoholic fermentation and softening of Chinese Winter Jujube fruits were promoted by 30 μL L^-1 NO during storage. The results indicated that 20 μL L^-1 NO could mitigate the injury of ethanol on Chinese Winter Jujube and effectively delay the browning and softening of fruits during storage.展开更多
The effects of application of cassava alcohol anaerobic fermentation liquid and mulching of film on overwintering and next year's growth and yield of banana were investigated in this study.The results showed that ...The effects of application of cassava alcohol anaerobic fermentation liquid and mulching of film on overwintering and next year's growth and yield of banana were investigated in this study.The results showed that the application of cassava alcohol anaerobic fermentation liquid with COD concentration of 1 200-2 000 mg/L(900 m^3/hm^2) and mulching of film significantly increased the soil organic matter and available potassium contents in banana orchard,improved the cold resistance of banana seedlings,increased the pseudostem height,pseudostem circumference,green leaf number and chlorophyll content of next year's banana seedlings,brought the flower bud emergence period and harvest period forward,and significantly increased the yield per plant.展开更多
The medium-chain fatty acid ethyl esters(MCFAEEs)are extremely important for the aroma profile of wines,and their metabolism process is influenced by the oxidation–reduction potential(ORP).However,the molecular mecha...The medium-chain fatty acid ethyl esters(MCFAEEs)are extremely important for the aroma profile of wines,and their metabolism process is influenced by the oxidation–reduction potential(ORP).However,the molecular mechanism by which ORP regulates MCFAEE production remains unclear.This study investigated these mechanisms based on transcriptome analysis of Saccharomyces cerevisiae under different ORPs during various stages of wine alcohol fermentation.The results showed that ORP regulation significantly changed the expression of genes involved in MCFAEE synthesis metabolic pathway.The expression level of pyruvate decarboxylase gene PDC6 was upregulated by 1.89-fold and 2.2-fold at 0 mV compared to100 mV during the early and middle fermentation stages,respectively.Similarly,aldehyde dehydrogenase gene ALD6 was upregulated by 1.8-fold at 0 mV relative to 60 mV in the late stage.Additionally,several genes involved in cell cycle,glutathione metabolism,the pentose phosphate pathway and MAPK signaling pathway,exhibited higher expression at 0 mV when compared to100 and 60 mV,which maybe thereby promote MCFAEE metabolism.These results establish a theoretical foundation for future research on the ORP regulation to improve the aroma quality of wines and provide a reference for the application of ORP operation in wine production.展开更多
The feasibility of pilot-scale manufacture of defined fungal starter and its application in rice wine production from different local starchy materials were investigated. Starter consisting of Arnylomyces rouxii and S...The feasibility of pilot-scale manufacture of defined fungal starter and its application in rice wine production from different local starchy materials were investigated. Starter consisting of Arnylomyces rouxii and Saccharomyces cerevisiae gave high performance in winemaking when prepared in conditions of rice flour 80% and cassava flour 20% with 4 incubation days. The starter level at 20% was favourably employed for manufacture with the initial amount of I0 kg mixed-flours, Dry starter granules which were vacuum packed could adapt ambient temperature （approx. 28-32℃） during 8 months of storage. The defined starter performed as superior inoculum for winemaking from different agricultural starchy resources. The undesirable bacteria were found at approx. 2 Log CFU/g of dry starter. By morphology, biochemical and physiological growth and the genetic partial 16S analyses, three bacterial isolates were characterized as Bacillus subtilis/amvloliquefaciens which may contaminate tbod but not cause food poisoning and not considered as a human pathogen.展开更多
Saccharifying activity of starter culture plays a key role on the simultaneous saccharification and fermentation of Chinese baijiu fermentation.However,the regulation of alcoholic fermentation by Daqu starter or sacch...Saccharifying activity of starter culture plays a key role on the simultaneous saccharification and fermentation of Chinese baijiu fermentation.However,the regulation of alcoholic fermentation by Daqu starter or saccharifying enzymes still remains unclear in the baijiu fermentation.In this study,we identified 13 proteins,affiliated to 4 saccharifying enzymes(including alpha-amylase,beta-amylase,glucoamylase and beta-glucosidase)as the key saccharifying enzymes in Daqu by metaproteomic and culture-dependent analysis.These enzymes were metabolized from plant substrate(13.4%)and microbial metabolism(86.6%),and especially alpha-amylase and glucoamylase from Aspergillus and Rhizopus were dominant in Daqu bio-system.Furthermore,we observed the dynamic of saccharifying activity of Daqu(from 241 to 395 U)was driven by the combinations of isolated saccharifying microbes responsible for key enzymes releasing,indicating AR7 group(with a ration of Rhizopus oryzae:Aspergillus oryzae in 10:1)presented the highest saccharifying activity(395 U)in a simulative Daqu production.However,the highest ethanol production(80.5 mg/g)was obtained from the fermentation driven by AR8 group(with a ration of Rhizopus oryzae:Aspergillus oryzae in 50:1)with the saccharifying activity of 389 U.These results indicated that a proper combination of saccharifying microbes could enhance the saccharifying activity of Daqu and then promote ethanol production in baijiu fermentation,as it did not always exhibit a positive correlativity between saccharifying activity and alcoholic fermentation.Our findings should provide a potential approach to regulate the alcoholic fermentation by optimizing the saccharifying microbes or enzymes of starter cultures for baijiu and other fermented food.展开更多
Cane molasses, a major byproduct in the sugar industry, is generally consumed for alcohol production. However, the alcohol production process needs to overcome three major challenges including increasing the productiv...Cane molasses, a major byproduct in the sugar industry, is generally consumed for alcohol production. However, the alcohol production process needs to overcome three major challenges including increasing the productivity of alcohol fermentation, lowering the energy consumption for alcohol conversion and decreasing the environmental pollution caused by the alcoholic yeast fermentation process. To meet these challenges, a screening process was conducted using 13 high osmotic tolerant yeast strains. Among the strains, a Saccharomyces cerevisiae strain 1912 was found to produce high alcohol concentrations during fermentation with high starting molasses concentrations such as 50% (W/V) molasses. In the test, 13.6% (V/V) alcohol was produced in the molasses fermentation broth after 72 h of incubation with an initial Yunnan molasses concentration of 50% in a 5 L fermentor. 15.0% (V/V) alcohol was obtained after 48 h of fermentation in shaking flasks containing 30% (W/V) initial total sugar concentration in diluted molasses. The performance of this strain in the shaking flasks was successfully scaled up to a 5 L fermentor vessel. Strain 1912 seems to be a better alcohol producer than the currently used alcohol production strain 2.1190.展开更多
Agave juice fermentation of native yeast strains in monoculture was studied for their fermentative capability and volatile and non-volatile compound production.The experiments were performed using agave juice suppleme...Agave juice fermentation of native yeast strains in monoculture was studied for their fermentative capability and volatile and non-volatile compound production.The experiments were performed using agave juice supplemented with ammonium sulfate.The results showed significant differences between genera of strains in the consumption of substrate and nitrogen source,as well as the formation of ethanol,biomass,and volatile and nonvolatile compounds.The compounds analyzed as minor volatile compounds included 42 volatile compounds classified into eight families:esters,alcohols,terpenes,acids,furans,phenols,aldehydes,and ketones.The agave juice fermented with Saccharomyces cerevisiae strains had higher levels of alcohols,acids,and terpenes than Kloeckera strains,while the highest concentrations of esters group,benzaldehyde,and acetoin compounds were observed in the Kloeckera strains.Seven volatile compounds were in a concentration above their thresholds associated with the attributes of‘banana’,‘apple’,‘malty’,‘citrus’,‘roses’,and‘clove’showed OAVs>1,suggesting that these compounds could significantly contribute to the perceived global aroma.Based on OAVs,the most potent odorant for Saccharomyces strains was isoamyl acetate,and in the case of Kloeckera strains was phenyl ethyl acetate;for both yeast genera,the following compounds showed OAVs>1:ethyl octanoate,ethyl hexanoate,isoamyl alcohol,eugenol,isoeugenol,andα-terpinene.The results demonstrate that the selection of yeast strain is critical for the efficiency of the fermentation and the tequila aroma profile design.The carbon balance carried out with the performance results of each yeast strain studied showed that the results obtained are consistent.展开更多
Irritable bowel syndrome(IBS) is one of the most common gastrointestinal disorders in Western countries. Despite the high prevalence of this disorders, the therapeutic management of these patients is often unsatisfact...Irritable bowel syndrome(IBS) is one of the most common gastrointestinal disorders in Western countries. Despite the high prevalence of this disorders, the therapeutic management of these patients is often unsatisfactory. A number of factors have been suggested to be involved in the pathogenesis of IBS, including impaired motility and sensitivity, increased permeability, changes in the gut microbiome and alterations in the brain-gut axis. Also food seems to play a critical role: the most of IBS patients report the onset or the exacerbation of their symptoms after the meals. Recently, an increasing attention has been paid to the role of food in IBS. In this review we summarize the most recent evidences about the role of diet on IBS symptoms. A diet restricted in fermentable, poorly absorbed carbohydrates and sugar alcohols has beneficial effects on IBS symptoms. More studies are needed to improve our knowledge about the relationship between food and IBS. However, in the foreseeable future, dietary strategies will represent one of the key tools in the therapeutic management of patients with IBS.展开更多
Saccharomyces cerevisiae is the main yeast used in the winemaking industry.Its innate glucophilicity provokes a discrepancy in glucose and fructose consumption during alcoholic fermentation of grape must,which,combine...Saccharomyces cerevisiae is the main yeast used in the winemaking industry.Its innate glucophilicity provokes a discrepancy in glucose and fructose consumption during alcoholic fermentation of grape must,which,combined with the inhibitory effect of ethanol accumulated in the fermentation broth,might lead to stuck or sluggish fermentations.In the present study,we realized an Adaptive Laboratory Evolution strategy,where an alcoholic fermentation of a 20 g/L fructose broth was followed by cell selection in a high ethanol concentration environment,employed in two different S.cerevisiae strains,named CFB and BLR.The evolved populations originated from each strain after 100 generations of evolution exhibited diverse fermentative abilities.One evolved population,originated from CFB strain,fermented a synthetic broth of 100 g/L glucose and 100 g/L fructose to dryness in 170 h,whereas the parental strain did not complete the fermentation even after 1000 h of incubation.The parameters of growth of the parental and evolved populations of the present study,as well as of the ethanol tolerant populations acquired in a previous study,when grown in a synthetic broth of 100 g/L glucose and 100 g/L fructose,were calculated through a kinetic model,and were compared to each other in order to identify the effect of evolution on the biochemical behavior of the strains.Finally,in a 200 g/L fructose synthetic broth fermentation,only the evolved population derived from CFB strain showed improved fermentative behavior than its parental strain.展开更多
Ziziphus jujuba pulp could be utilized for Ziziphus jujuba vinegar(ZJV)production to reduce waste.However,how to specifically regulate microorganisms during ZJV fermentation to improve its flavor remains an industrial...Ziziphus jujuba pulp could be utilized for Ziziphus jujuba vinegar(ZJV)production to reduce waste.However,how to specifically regulate microorganisms during ZJV fermentation to improve its flavor remains an industrial problem.This study evaluated the contribution of ZJV's two-stage fermentation(alcohol fermentation(AF)and acetic acid fermentation(AAF))to flavor metabolites and microbial community assembly.The ZJV production can represent a sustainable strategy in the management of Ziziphus jujuba pulp wastes.Temperature,alcohol and acid were driving forces of microbiota succession.AF is an important stage for the formation of alcohols,esters,non-volatile acids,and various amino acids.Bacteria and fungi mainly generated esters and alcohols in AF,respectively.Microorganisms capable of protease production and strong stress resistance were conducive to amino acid production(e.g.,Virgibacillus and Saccharomyces in AF,Bacillus and Xeromyces in AAF).Solid-state AAF was the key step of acetic acid production and flavor metabolite accumulation.Komagataeibacter with higher acid-tolerant than Acetobacter dominated late AAF and showed a positive correlation with acetic acid.Dominant bacteria promoted the accumulation of various volatile flavor substances(esters,acids,aldehydes,and ketones),while low-abundance fungi facilitated the accumulation of functional metabolites(GABA,acetoin,tetramethylpyrazine).These results guided the targeted control of ZJV fermentation to improve its flavor quality and provided valuable insights for ZJV manufacturers.展开更多
The growing interest in novel beer development determined the exploitation of unconventional yeasts isolated from novel ecological niches to generate unexplored sensory profiles.In recent years,there is an increasing ...The growing interest in novel beer development determined the exploitation of unconventional yeasts isolated from novel ecological niches to generate unexplored sensory profiles.In recent years,there is an increasing interest in generating beers brewed with the addition of fruits.For the first time,Lachancea thermotolerans MNF105 and Saccharomyces cerevisiae MN113 isolated from manna,were tested as starter cultures to process loquat beer to improve the sensory profile.Innovatively,the yeast species L.thermotolerans was investigated for the production of sour fruit beer.Sour fruit beers produced with L.thermotolerans MNF105 were more balanced than the respective control,especially in terms of perceived acidity during sensory analysis.This could be due to the lower lactic acid production(0.49 g/L)compared to the respective control(1.74 g/L).The overall organoleptic investigation showed a preference for S.cerevisiae MN113(TF1)isolated from manna.Experimental trials conducted with the selected strains demonstrated the absence of off-odour and off-flavour and improved aroma perception.Aldehydes and alcohols were the most abundant compounds emitted from the beers.S.cerevisiae MN113 and L.thermotolerans MNF105,manna related yeasts,showed great technological properties,representing promising starters for the production of fruit beer and sour fruit beer.展开更多
基金financed by the Green Fund of the Hellenic Ministry of Environment and Energy,under the funding program“National Environment and Innovation Activities 2022”,Priority Axis“Research&Application”,Project“Sustainable technology for converting pomegranate residues into bioproducts and bioactive compounds”with the acronym“POMEGRANATE”.
文摘Pomegranate residues(PRs),namely pomegranate peels and seeds remaining after juice extraction,constitute a significant agro-industrial residue in Greece.Despite their ample content in carbon sources and bioactive compounds,PRs are largely unexploited,with their management being an increasing concern for the pome-granate processing industry.The objective of this study was the development and characterization of a bio-process aiming at the biotechnological valorization of PRs for ethanol production.Specifically,a stepwise investigation was conducted,including(i)the production and chemical characterization of extracts/hydrolysates from PRs using distinct pretreatments not involving organic solvents or enzymatic hydrolysis;(ii)the assessment of the exploitability of a selected hydrolysate as fermentation feedstock using Saccharomyces cerevisiae;and(iii)the advancement of the bioprocess through the joined utilization in the fermentation substrate of PRs and seeded raisins(SRs),another important agro-industrial residue in Greece.The finally developed substrate,comprising a mixture of PRs/SRs extracts at concentrations 60/40%v/v,was used in three fermentation trials,and the fermentation process was quantitatively described using the Aiba model.The developed bioprocess resulted in satisfactorily high bioethanol production with the maximum attained concentration being 50.0±0.6 g/L.The maximum specific growth rate(μ_(max))of S.cerevisiae was estimated to be 0.1351/h and the bioethanol yield(Y_(ps)),namely the amount of produced ethanol/amount of consumed reducing sugars,was estimated to be 0.423 g/g.Hence,PRs can be efficiently used in the development of a fermentation substrate for bioethanol production,providing an economic and environmentally sustainable alternative to conventional feedstocks.
文摘This article investigates the effects of nitric oxide （NO） on alcoholic fermentation and the qualities of Chinese Winter Jujube during storage, and explores the action mechanisms of browning and softening of fruits to provide theoretical proofs for using NO in the storage of Chinese Winter Jujube. Chinese Winter Jujube fruits were fumigated with different concentrations of NO gas （0, 10, 20, 30 μL L^-1） under anaerobic conditions and stored at 22±1℃ and 4± 1℃. The changes in appearance qualities, the contents of pyruvate, ethanol, acetaldehyde, and the activities of alcohol dehydrogenase （ADH） and lactate dehydrogenase （LDH） were investigated. The contents of pyruvate, ethanol, and acetaldehyde were significantly reduced, and the peak of pyruvate content was delayed by 20 μL L^-1 NO. The activities of ADH and LDH in 20 μL L^-1 NO treated fruits were also significantly inhibited. However, the alcoholic fermentation and softening of Chinese Winter Jujube fruits were promoted by 30 μL L^-1 NO during storage. The results indicated that 20 μL L^-1 NO could mitigate the injury of ethanol on Chinese Winter Jujube and effectively delay the browning and softening of fruits during storage.
基金Supported by National Natural Science Foundation of China(31260461)2013 Guiding Fund for Ecological Guangxi Construction+2 种基金Guangxi Scientific Research and Technological Development Project(GKH 1346011-19)Students’Experimental Skills and Scientific and Technological Innovation Ability Training Fund of Guangxi University(SYJN20131513)Earmarked Fund for Nanning Station of Banana in Guangxi of China Agriculture Research System(nycytxcxtd-04-18)
文摘The effects of application of cassava alcohol anaerobic fermentation liquid and mulching of film on overwintering and next year's growth and yield of banana were investigated in this study.The results showed that the application of cassava alcohol anaerobic fermentation liquid with COD concentration of 1 200-2 000 mg/L(900 m^3/hm^2) and mulching of film significantly increased the soil organic matter and available potassium contents in banana orchard,improved the cold resistance of banana seedlings,increased the pseudostem height,pseudostem circumference,green leaf number and chlorophyll content of next year's banana seedlings,brought the flower bud emergence period and harvest period forward,and significantly increased the yield per plant.
基金supported by the Key Science and Tech-nology Project of Xinjiang Uygur Autonomous Region(2022A02002-4)the Basic Research Program of Natural Science in Shaanxi Province(2023-JC-YB-145)the National Natural Science Foundation of China(31801528).
文摘The medium-chain fatty acid ethyl esters(MCFAEEs)are extremely important for the aroma profile of wines,and their metabolism process is influenced by the oxidation–reduction potential(ORP).However,the molecular mechanism by which ORP regulates MCFAEE production remains unclear.This study investigated these mechanisms based on transcriptome analysis of Saccharomyces cerevisiae under different ORPs during various stages of wine alcohol fermentation.The results showed that ORP regulation significantly changed the expression of genes involved in MCFAEE synthesis metabolic pathway.The expression level of pyruvate decarboxylase gene PDC6 was upregulated by 1.89-fold and 2.2-fold at 0 mV compared to100 mV during the early and middle fermentation stages,respectively.Similarly,aldehyde dehydrogenase gene ALD6 was upregulated by 1.8-fold at 0 mV relative to 60 mV in the late stage.Additionally,several genes involved in cell cycle,glutathione metabolism,the pentose phosphate pathway and MAPK signaling pathway,exhibited higher expression at 0 mV when compared to100 and 60 mV,which maybe thereby promote MCFAEE metabolism.These results establish a theoretical foundation for future research on the ORP regulation to improve the aroma quality of wines and provide a reference for the application of ORP operation in wine production.
文摘The feasibility of pilot-scale manufacture of defined fungal starter and its application in rice wine production from different local starchy materials were investigated. Starter consisting of Arnylomyces rouxii and Saccharomyces cerevisiae gave high performance in winemaking when prepared in conditions of rice flour 80% and cassava flour 20% with 4 incubation days. The starter level at 20% was favourably employed for manufacture with the initial amount of I0 kg mixed-flours, Dry starter granules which were vacuum packed could adapt ambient temperature （approx. 28-32℃） during 8 months of storage. The defined starter performed as superior inoculum for winemaking from different agricultural starchy resources. The undesirable bacteria were found at approx. 2 Log CFU/g of dry starter. By morphology, biochemical and physiological growth and the genetic partial 16S analyses, three bacterial isolates were characterized as Bacillus subtilis/amvloliquefaciens which may contaminate tbod but not cause food poisoning and not considered as a human pathogen.
基金supported by National Natural Science Foundation of China(NSFC)(32102119)National Key R&D Program of China(2022YFD2101205)+1 种基金Program of Baijiu Technology Innovation Strategy of China Alcoholic Drinks Association(202105)Hebei Province Science and Technology Plan Project(215A9935D).
文摘Saccharifying activity of starter culture plays a key role on the simultaneous saccharification and fermentation of Chinese baijiu fermentation.However,the regulation of alcoholic fermentation by Daqu starter or saccharifying enzymes still remains unclear in the baijiu fermentation.In this study,we identified 13 proteins,affiliated to 4 saccharifying enzymes(including alpha-amylase,beta-amylase,glucoamylase and beta-glucosidase)as the key saccharifying enzymes in Daqu by metaproteomic and culture-dependent analysis.These enzymes were metabolized from plant substrate(13.4%)and microbial metabolism(86.6%),and especially alpha-amylase and glucoamylase from Aspergillus and Rhizopus were dominant in Daqu bio-system.Furthermore,we observed the dynamic of saccharifying activity of Daqu(from 241 to 395 U)was driven by the combinations of isolated saccharifying microbes responsible for key enzymes releasing,indicating AR7 group(with a ration of Rhizopus oryzae:Aspergillus oryzae in 10:1)presented the highest saccharifying activity(395 U)in a simulative Daqu production.However,the highest ethanol production(80.5 mg/g)was obtained from the fermentation driven by AR8 group(with a ration of Rhizopus oryzae:Aspergillus oryzae in 50:1)with the saccharifying activity of 389 U.These results indicated that a proper combination of saccharifying microbes could enhance the saccharifying activity of Daqu and then promote ethanol production in baijiu fermentation,as it did not always exhibit a positive correlativity between saccharifying activity and alcoholic fermentation.Our findings should provide a potential approach to regulate the alcoholic fermentation by optimizing the saccharifying microbes or enzymes of starter cultures for baijiu and other fermented food.
文摘Cane molasses, a major byproduct in the sugar industry, is generally consumed for alcohol production. However, the alcohol production process needs to overcome three major challenges including increasing the productivity of alcohol fermentation, lowering the energy consumption for alcohol conversion and decreasing the environmental pollution caused by the alcoholic yeast fermentation process. To meet these challenges, a screening process was conducted using 13 high osmotic tolerant yeast strains. Among the strains, a Saccharomyces cerevisiae strain 1912 was found to produce high alcohol concentrations during fermentation with high starting molasses concentrations such as 50% (W/V) molasses. In the test, 13.6% (V/V) alcohol was produced in the molasses fermentation broth after 72 h of incubation with an initial Yunnan molasses concentration of 50% in a 5 L fermentor. 15.0% (V/V) alcohol was obtained after 48 h of fermentation in shaking flasks containing 30% (W/V) initial total sugar concentration in diluted molasses. The performance of this strain in the shaking flasks was successfully scaled up to a 5 L fermentor vessel. Strain 1912 seems to be a better alcohol producer than the currently used alcohol production strain 2.1190.
基金funded by CONACYT Consejo Nacional de Ciencia y Tecnología(Mexican National Council of Science and Technology)with the project SEP-CONACYT 24547.
文摘Agave juice fermentation of native yeast strains in monoculture was studied for their fermentative capability and volatile and non-volatile compound production.The experiments were performed using agave juice supplemented with ammonium sulfate.The results showed significant differences between genera of strains in the consumption of substrate and nitrogen source,as well as the formation of ethanol,biomass,and volatile and nonvolatile compounds.The compounds analyzed as minor volatile compounds included 42 volatile compounds classified into eight families:esters,alcohols,terpenes,acids,furans,phenols,aldehydes,and ketones.The agave juice fermented with Saccharomyces cerevisiae strains had higher levels of alcohols,acids,and terpenes than Kloeckera strains,while the highest concentrations of esters group,benzaldehyde,and acetoin compounds were observed in the Kloeckera strains.Seven volatile compounds were in a concentration above their thresholds associated with the attributes of‘banana’,‘apple’,‘malty’,‘citrus’,‘roses’,and‘clove’showed OAVs>1,suggesting that these compounds could significantly contribute to the perceived global aroma.Based on OAVs,the most potent odorant for Saccharomyces strains was isoamyl acetate,and in the case of Kloeckera strains was phenyl ethyl acetate;for both yeast genera,the following compounds showed OAVs>1:ethyl octanoate,ethyl hexanoate,isoamyl alcohol,eugenol,isoeugenol,andα-terpinene.The results demonstrate that the selection of yeast strain is critical for the efficiency of the fermentation and the tequila aroma profile design.The carbon balance carried out with the performance results of each yeast strain studied showed that the results obtained are consistent.
文摘Irritable bowel syndrome(IBS) is one of the most common gastrointestinal disorders in Western countries. Despite the high prevalence of this disorders, the therapeutic management of these patients is often unsatisfactory. A number of factors have been suggested to be involved in the pathogenesis of IBS, including impaired motility and sensitivity, increased permeability, changes in the gut microbiome and alterations in the brain-gut axis. Also food seems to play a critical role: the most of IBS patients report the onset or the exacerbation of their symptoms after the meals. Recently, an increasing attention has been paid to the role of food in IBS. In this review we summarize the most recent evidences about the role of diet on IBS symptoms. A diet restricted in fermentable, poorly absorbed carbohydrates and sugar alcohols has beneficial effects on IBS symptoms. More studies are needed to improve our knowledge about the relationship between food and IBS. However, in the foreseeable future, dietary strategies will represent one of the key tools in the therapeutic management of patients with IBS.
文摘Saccharomyces cerevisiae is the main yeast used in the winemaking industry.Its innate glucophilicity provokes a discrepancy in glucose and fructose consumption during alcoholic fermentation of grape must,which,combined with the inhibitory effect of ethanol accumulated in the fermentation broth,might lead to stuck or sluggish fermentations.In the present study,we realized an Adaptive Laboratory Evolution strategy,where an alcoholic fermentation of a 20 g/L fructose broth was followed by cell selection in a high ethanol concentration environment,employed in two different S.cerevisiae strains,named CFB and BLR.The evolved populations originated from each strain after 100 generations of evolution exhibited diverse fermentative abilities.One evolved population,originated from CFB strain,fermented a synthetic broth of 100 g/L glucose and 100 g/L fructose to dryness in 170 h,whereas the parental strain did not complete the fermentation even after 1000 h of incubation.The parameters of growth of the parental and evolved populations of the present study,as well as of the ethanol tolerant populations acquired in a previous study,when grown in a synthetic broth of 100 g/L glucose and 100 g/L fructose,were calculated through a kinetic model,and were compared to each other in order to identify the effect of evolution on the biochemical behavior of the strains.Finally,in a 200 g/L fructose synthetic broth fermentation,only the evolved population derived from CFB strain showed improved fermentative behavior than its parental strain.
基金funded by Hebei Natural Science Foundation(C2020208014)S&T Program of Hebei(22327107D).
文摘Ziziphus jujuba pulp could be utilized for Ziziphus jujuba vinegar(ZJV)production to reduce waste.However,how to specifically regulate microorganisms during ZJV fermentation to improve its flavor remains an industrial problem.This study evaluated the contribution of ZJV's two-stage fermentation(alcohol fermentation(AF)and acetic acid fermentation(AAF))to flavor metabolites and microbial community assembly.The ZJV production can represent a sustainable strategy in the management of Ziziphus jujuba pulp wastes.Temperature,alcohol and acid were driving forces of microbiota succession.AF is an important stage for the formation of alcohols,esters,non-volatile acids,and various amino acids.Bacteria and fungi mainly generated esters and alcohols in AF,respectively.Microorganisms capable of protease production and strong stress resistance were conducive to amino acid production(e.g.,Virgibacillus and Saccharomyces in AF,Bacillus and Xeromyces in AAF).Solid-state AAF was the key step of acetic acid production and flavor metabolite accumulation.Komagataeibacter with higher acid-tolerant than Acetobacter dominated late AAF and showed a positive correlation with acetic acid.Dominant bacteria promoted the accumulation of various volatile flavor substances(esters,acids,aldehydes,and ketones),while low-abundance fungi facilitated the accumulation of functional metabolites(GABA,acetoin,tetramethylpyrazine).These results guided the targeted control of ZJV fermentation to improve its flavor quality and provided valuable insights for ZJV manufacturers.
基金partially funded by the Sicily Region research project“AINEB 50 Living Lab Nebrodi-Comune di Galati Mamertino(Messina Province,Sicily)”CUP:F47H20003430009.
文摘The growing interest in novel beer development determined the exploitation of unconventional yeasts isolated from novel ecological niches to generate unexplored sensory profiles.In recent years,there is an increasing interest in generating beers brewed with the addition of fruits.For the first time,Lachancea thermotolerans MNF105 and Saccharomyces cerevisiae MN113 isolated from manna,were tested as starter cultures to process loquat beer to improve the sensory profile.Innovatively,the yeast species L.thermotolerans was investigated for the production of sour fruit beer.Sour fruit beers produced with L.thermotolerans MNF105 were more balanced than the respective control,especially in terms of perceived acidity during sensory analysis.This could be due to the lower lactic acid production(0.49 g/L)compared to the respective control(1.74 g/L).The overall organoleptic investigation showed a preference for S.cerevisiae MN113(TF1)isolated from manna.Experimental trials conducted with the selected strains demonstrated the absence of off-odour and off-flavour and improved aroma perception.Aldehydes and alcohols were the most abundant compounds emitted from the beers.S.cerevisiae MN113 and L.thermotolerans MNF105,manna related yeasts,showed great technological properties,representing promising starters for the production of fruit beer and sour fruit beer.
