A plant fermentation was carried out by Yeast and Lactobacilli against single cellular algae (f-Chlorella). These materials were proved by as safe in animal safety experiment. We sought to look into changes of immune-...A plant fermentation was carried out by Yeast and Lactobacilli against single cellular algae (f-Chlorella). These materials were proved by as safe in animal safety experiment. We sought to look into changes of immune-competent cells that commonly utilized f-Chlorella including after administration of immno-suppressed animals. The effects by f-Chlorella on the regurational effect to the host were measured. Our results showed that f-Chlorella regulated the level of lymphocytes, while conventional-Chlorella worked to adjust the level of granulocytes. In our clinical study with 20 healthy volunteers, granulocyte and lymphocyte ratio was obtained as neutral in the peripheral blood. In rodents, immune-compromised host as well as normal animal were prepared with cancer chemotherapeutic agent (Mytomycin-C), and then tried to rescue the immune-competent rebel. Our observations showed that both Chlorella derivatives regulated in number and functions. The effect was more prominent in f-Chlorella than that of conventional one. We discussed the significance and mechanism of f-Chlorella on the level of leukocyte subsets in number and function. These effects were considered to bring the potential elevation of antibody secreting cell by the localized heamolysis in gel method. We also proposed an idea that exhibited tonic effects were brought via activating the complement components in the serum. Moreover, we tried to access further to the anti-oxidative activities of this f-Chlorella. This modification brought to the significant lifted up for immune competent cells and anti-oxidative activity for phagocytic cells.展开更多
Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic fermentation.Such influences are imposed on yeast growth and fermentation performances inclu...Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic fermentation.Such influences are imposed on yeast growth and fermentation performances including the formation of secondary metabolites.Saccharomyces cerevisiae,the main yeast responsible for fermentation,has been studied extensively regarding nitrogen impacts.On the other hand,a similar study for non-Saccharomyces yeasts,whose contributions to winemaking have gradually been acknowledged,remains to be fully explored,with a few studies being reported.This review starts by discussing nitrogen impacts on non-Saccharomyces yeast growth and fermentation kinetics in different case scenarios,then proceeds to summarize the nitrogen preferences of individual yeast strains with regulation mechanisms elucidated by recent studies.Detailed discussions on the influences on the production of volatile compounds and proposed pathways therein are made,followed by future work suggested as the final section.In summarizing the nitrogen impacts on non-Saccharomyces yeasts throughout alcoholic fermentation,this review will be helpful in obtaining a more comprehensive view on these non-conventional wine yeasts in terms of nutrient requirements and corresponding volatile production.Research gaps will therefore be elucidated for future research.展开更多
The budding yeast Saccharomyces cerevisiae is a powerful model system for studying the cell polarity establishment.The cell polarization process is regulated by signaling molecules,which are initially distributed in t...The budding yeast Saccharomyces cerevisiae is a powerful model system for studying the cell polarity establishment.The cell polarization process is regulated by signaling molecules,which are initially distributed in the cytoplasm and then recruited to a proper location on the cell membrane in response to spatial cues or spontaneously.Polarization of these signaling molecules involves complex regulation,so the mathematical models become a useful tool to investigate the mechanism behind the process.In this review,we discuss how mathematical modeling has shed light on different regulations in the cell polarization.We also propose future applications for the mathematical modeling of cell polarization and morphogenesis.展开更多
Sorghum beer or dolo is part of the eating habits of part of the population of Dédougou because of its low price compared with industrial beers. Its production is an ancestral tradition that uses traditional equi...Sorghum beer or dolo is part of the eating habits of part of the population of Dédougou because of its low price compared with industrial beers. Its production is an ancestral tradition that uses traditional equipment and gives dolo organoleptic properties that are not found in industrial beers. The production process involves several stages, including fermentation, which itself comprises natural lactic fermentation followed by alcoholic fermentation using traditional yeasts, which are not controlled in any way. The general aim of this study is to assess the microbiological quality of these fermentative yeasts in the town of Dédougou, in order to contribute to the health safety of the population and the promotion of these local beers. Twenty samples of fermenting yeast were analyzed according to ISO standards, to isolate enterobacteria, total and faecal coliforms according to standard procedures for isolating these micro-organisms. The isolated strains were identified using the API20E gallery. Microbiological analyses revealed the presence of 51.17% enterobacteria, 45.38% total coliforms and 3.45% thermotolerant coliforms. We counted 40% Escherichia coli, 20% Enterobacter cloacae, 20% Klebsiella pneumoniae and 20% Klebsiella spp. All the strains detected are capable of surviving in hostile conditions and could harm the quality of the dolo, consumer health and cause real collective food poisoning in the town of Dédougou. This enabled us to assess the microbial quality of these yeasts and to propose more suitable measures for producing and preserving dolo under hygienic conditions to protect consumer health.展开更多
Background There is a growing search for natural feed additives to alleviate the deleterious effects of coccidia infection in poultry production.This study aimed to investigate the effect of enzymatically treated yeas...Background There is a growing search for natural feed additives to alleviate the deleterious effects of coccidia infection in poultry production.This study aimed to investigate the effect of enzymatically treated yeast(ETY) on the growth performance,nutrient digestibility,intestinal morphology,antioxidative status,and cecal mucosa cytokines of coccidia-challenged broiler chickens.Methods From d 1 to 14 post hatching,480 broiler chickens were allocated to 3 corn-soybean meal-based experimental diets with increasing concentrations of ETY(0,1,or 2 g/kg).The experiment was designed as a randomized complete block design with body weight(BW) used as a blocking factor.On d 14 post hatching,the birds were re-randomized within each of the 3 experimental diets.Each of the 3 diet groups was split into a challenge or no-challenge group.This resulted in a 3 × 2 factorial arrangement of treatments.The coccidia challenge was administered on d 15 by an oral gavage.Results Dietary ETY improved(P < 0.05) the G:F of birds on d 21 regardless of the challenge state and linearly increased(P < 0.01) the apparent ileal digestibility of dry matter(DM),nitrogen,and gross energy(GE).The coccidia challenge decreased(P < 0.05) BW gain and feed intake of broiler chickens and reduced(P < 0.01) the total tract retention of DM,GE,and nitrogen.The coccidia challenge increased(P < 0.01) the mRNA gene expression of TNFα,IL-1β,IL-10,and IL-6 in the cecal mucosa.There was a tendency(P ne = 0.08) for ETY to linearly reduce IL-1β expression.Additionally,ETY supplementation increased(P < 0.05) the geexpression of OCLN.Serum catalase increased(P < 0.05) with dietary ETY in broiler chickens on d 21.Dietary ETY linearly increased(P < 0.05) the ileal villus height to crypt depth ratio,and ileal goblet cell density in broiler chickens.The ileal and excreta oocyst counts decreased(P < 0.01) with increasing supplementation of dietary ETY in coccidia-challenged broiler chickens on d 21.Conclusions Dietary ETY enhanced nutrient utilization and augmented intestinal development in broiler chickens.However,dietary ETY did not completely attenuate the adverse effects of a coccidia challenge in broiler chickens.展开更多
Micro-environmental restriction effects to yeast cell growth obtained within Ca-alginate microbeads are considered. It is complex phenomenon influenced by: (1) relaxation of expanded polymer network around the cellula...Micro-environmental restriction effects to yeast cell growth obtained within Ca-alginate microbeads are considered. It is complex phenomenon influenced by: (1) relaxation of expanded polymer network around the cellular clusters, (2) forces generated by cell growth inside the beads and (3) interactions between solvent, network parts and cells. The resulting effects are measured experimentally by estimating volume of microbeads and yeast cell concentration as function of time of cultivation. Comparative analysis of dynamics of cell growth and increase of microbead volume through four regimes indicates that reversible and irreversible local structural changes of Ca-alginate hydrogel induces micro-environmental restrictions to cell growth. The mechanism of restrictions includes both mechanical and electrostatic effects.展开更多
Pectinases are used in Enology for some different utilities. Enzymatic preparations from moulds are a mixed of different enzymes with strong and unspe-cific activities. Some Saccharomyces cerevisiae pro-duce pectinase...Pectinases are used in Enology for some different utilities. Enzymatic preparations from moulds are a mixed of different enzymes with strong and unspe-cific activities. Some Saccharomyces cerevisiae pro-duce pectinases which can be used instead of com-mercial preparations. The objectives of this work were to study the enzyme secretion by one Saccharo-myces cerevisiae (CECT 11783) for growing on grape skin (industry oenological by-product) as carbon source. Preliminary experiments showed that the strain produced pectinases for growing on grape skin without any other carbon source. Statistical treat-ment (factorial design 25) was applied to evaluate the influences of related factors (agitation, temperature, presence of peptone and detergent in the medium and time of growth) Variables with the most significant interactions for pectinase production were agitation and nitrogen source concentration. Response surface methodology showed that a first order model was not adequate for results. Nevertheless, the built of a sec-ond order model offered a polynomial equation which surface predicted a maximum of activity (52.68 enzymatic units) for specific values of the studied variables (147.8 rpm of agitation and 15.9 g of pep-tone/ L culture medium).展开更多
Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of th...Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of the Smc1-Smc3-Scc1 cohesin ring, is phosphorylated on S/T-Q residues. This event depended on the Mec1 checkpoint kinase as well as on cell cycle arrest triggered by the DNA damage checkpoint network. This phosphorylation event also took place during mitosis of an unperturbed cell cycle. The present finding that S. cerevisiae Scc3 is phosphorylated during mitosis represents a potentially important new regulatory step in cohesin’s mitotic functions.展开更多
Ethyl caproate and isoamyl alcohol are important for the quality of Yakju, one of the Korean traditional alcoholic beverages. From Korean traditional fermentation agent, Nuruk, we have isolated 8 yeasts which produced...Ethyl caproate and isoamyl alcohol are important for the quality of Yakju, one of the Korean traditional alcoholic beverages. From Korean traditional fermentation agent, Nuruk, we have isolated 8 yeasts which produced rich aromatic compounds using YEPD agar plates (1% yeast extract, 2% peptone, 2% dextrose, 2% agar) containing 50 uL cerulenin at 30℃. The isolated aromatic yeasts are identified as Pichia anomala (4 strains), Pichia fabianii (2 strains), Pichia farinose (1 strains), Geotrichum candidum (1 strains). We conducted alcohol fermentation with each of the aromatic yeasts and the compounds (ethyl caproate and isoamyl alcohol) producing range were 59.5 - 193.2 ppm and 10.8 - 91.6 ppm respectively. As a control, Fermivin®, famous aromatic wine yeast, was 89.4 ppm and 16.2 ppm respectively. We also find that the isolated Pichia anomala could produce higher level ethanol (4.2% - 5.0%, v/v) than other species (0.4% - 2.2%, v/v). Using the aromatic yeasts in fermentation industries, we expect to improve the quality of traditional alcoholic beverages.展开更多
Higher levels of acetaldehyde in beer are one of the major concerns in the current beer industry.Yeast produces acetaldehyde during alcoholic fermentation,and its modification significantly affects beer flavor and qua...Higher levels of acetaldehyde in beer are one of the major concerns in the current beer industry.Yeast produces acetaldehyde during alcoholic fermentation,and its modification significantly affects beer flavor and quality.A different mutant strain with lower acetaldehyde production and improved ethanol tolerance was constructed using the ARTP-ALE mutagenesis strategy with 4-methylpyrazole-disulfiram.As a result of the mutation,the alcohol dehydrogenase activity of the mutant strain decreased to about 71.22%of that of the wild-type strain.At the same time,the fermentation properties and genetic stability of the newly screened strain showed slight differences from the wild-type strain,and there were no safety concerns regarding industrial use of the mutant strain.展开更多
The yeast MATα1 is required for the activation of α-specific genes in Saccharomyces cerevisiae and thus confers the α-cell identity of the yeast. MATα1 contains a domain called the α-domain which has significant ...The yeast MATα1 is required for the activation of α-specific genes in Saccharomyces cerevisiae and thus confers the α-cell identity of the yeast. MATα1 contains a domain called the α-domain which has significant sequence identity to the HMG-box family of proteins. A multiple sequence alignment of several α-domains and various structurally determined HMG-box domains has revealed that both domains possess very similar structural and functional residues. We found that the basic amino acids of the N-terminal loop, the intercalating hydrophobic residues of the first helix, and the hydrophobic residues required for interactions within the core of the protein are remarkably conserved in α-domains and HMG-box proteins. Our generated molecular models suggest that the first and third helix will be shorter and that the HMG-box core is not an isolated domain. The region beyond the conserved HMG-box motif contains an extended helical region for about 20 - 30 amino acids. Structural models generated by comparative modeling and ab initio modeling reveal that this region will add two or more additional α-helices and will make significant contacts to helix III, II and I of the HMG-box core. We were able to illustrate how the extended α-domain would bind to DNA by merging of the α-domain and the LEF-1/DNA complex. The models we are reporting will be helpful in understanding how MATα1 binds to DNA with its partner MCM1 and activates transcription of α-specific genes. These models will also aid in future biophysical studies of MATα1 including the crystallization and structure determination.展开更多
Purpose: In a placebo-controlled, double-blind, randomized clinical trial, the effect of an insoluble yeast beta-glucan preparation on the incidences of common colds and its effect on common cold symptoms were compare...Purpose: In a placebo-controlled, double-blind, randomized clinical trial, the effect of an insoluble yeast beta-glucan preparation on the incidences of common colds and its effect on common cold symptoms were compared to placebo. Methods: 100 healthy participants with recurring infections were randomly assigned to receive either placebo or yeast beta-glucan (Yestimun?;n = 50 each group) over a period of 26 weeks. The subjects had to document each common cold episode in a diary, and rate 6 predefined infections symptoms on a 3-point rating scale during an infection period, resulting in an infection score. The common cold episodes were confirmed by the investigators. Results: A total of 171 common cold episodes were documented. Of these, 76 were experienced by 38 subjects in the beta-glucan group and 96 were experienced by 48 subjects in the placebo group (p = 0.406). The beta-glucan group had significantly more subjects without incidences of common cold than the placebo group (15.6% vs 2.0%;p = 0.019). During the most intense infection season (first 13 weeks of the study), the beta-glucan group had significantly less infections compared to placebo (p = 0.02). Beta-glucan significantly reduced the typical cold symptoms (“sore throat and/or difficulty swallowing”, “hoarseness and/or cough” and “runny nose”) as opposed to placebo. Conclusion: The present study demonstrates a prophylactic effect of yeast beta-glucan on the occurrence of common colds as opposed to placebo. In addition, when these episodes occurred, they were from the beginning less pronounced and subsided faster.展开更多
For practical applications of bioethanol, the uses of both highly concentrated biomass materials and their effective fermentation by yeasts are indispensable in order to produce ethanol at low costs. However, as the s...For practical applications of bioethanol, the uses of both highly concentrated biomass materials and their effective fermentation by yeasts are indispensable in order to produce ethanol at low costs. However, as the saccharified products of those biomass generally contain abundant sugars, the yeasts are affected by the compounds and are inclined to decrease their physiological activities. In the process of fermentation, ethanol is gradually produced by the yeasts in the culture;the concentrated metabolic product also damages itself, and inhibition of the fermentation frequently occurs. The application of yeasts with high fermentative activities under stress pressures such as sugars and ethanol is thus desired for bioethanol production. In this study, various types of high-fermentative yeasts under stress pressures were isolated mainly from coastal waters in Japan and characterized. All yeast strains with high fermentative activities under 20% v/v ethanol were found to be Saccharomyces cerevisiae. The HK21 strain isolated from Tokyo Bay and identified as S. cerevisiae had the highest fermentation activity under 30% w/v sorbitol and under 20% v/v ethanol, and it produced approx. 70 g/l (9% v/v) ethanol from the 15% w/v glucose solution at 25 oC within 5 days.展开更多
Background Intestinal inflammation is the main risk factor causing intestinal barrier dysfunction and lipopolysaccharide(LPS)can trigger inflammatory responses in various eukaryotic species.Yeast hydrolysate(YH)posses...Background Intestinal inflammation is the main risk factor causing intestinal barrier dysfunction and lipopolysaccharide(LPS)can trigger inflammatory responses in various eukaryotic species.Yeast hydrolysate(YH)possesses multibiological effects and is received remarkable attention as a functional ingredient for improving growth performance and promoting health in animals.However,there is still inconclusive on the protective effects of dietary YH supplementation on intestinal barrier of piglets.This study was conducted to investigate the attenuate effects of YH supplementation on inflammatory responses and intestinal barrier injury in piglets challenged with LPS.Methods Twenty-four piglets(with an average body weight of 7.42±0.34 kg)weaned at 21 days of age were randomly assigned to one of two dietary treatments(12 replications with one pig per pen):a basal diet or a basal diet containing YH(5 g/kg).On the 22nd d,6 piglets in each treatment were intraperitoneally injected with LPS at 150μg/kg BW,and the others were injected with the same amount of sterile normal saline.Four hours later,blood samples of each piglet were collected and then piglets were euthanized.Results Dietary YH supplementation increased average daily feed intake and average daily gain(P<0.01),decreased the ratio of feed intake to gain of piglets(P sponse,evidenced by the increase o=0.048).Lipopolysaccharide(LPS)injection induced systemic inflammatory ref serum concentrations of haptoglobin(HP),adrenocorticotropic hormone(ACTH),cortisol,and interleukin-1β(IL-1β).Furthermore,LPS challenge resulted in inflammatory intestinal damage,by up-regulation of the protein or mRNA abundances of tumor necrosis factor-α(TNF-α),IL-1β,toll-like receptors 4(TLR4)and phosphor-nuclear factor-κB-p65(p-NFκB-p65)(P<0.01),and down-regulation of the jejunal villus height,the protein and mRNA abundances of zonula occludens-1(ZO-1)and occludin(OCC;P<0.05)in jejunal mucosa.Dietary YH supplementation decreased the impaired effects of ACTH,cortisol,HP,IL-1βand diamine oxidase in serum(P<0.05).Moreover,YH supplementation also up-regulated the jejunal villus height,protein and mRNA abundances of ZO-1 and OCC(P<0.05),down-regulated the mRNA expressions of TNF-αand IL-1βand the protein abundances of TNF-α,IL-1β,TLR4 and p-NFκB-p65 in jejunal mucosa in LPS-challenged pigs(P<0.01).Conclusion Yeast hydrolysate could attenuate inflammatory response and intestinal barrier injury in weaned piglets challenged with LPS,which was associated with the inhibition of TLR4/NF-κB signaling pathway activation.展开更多
Yeasts play a critical role in the flavor formation of dry-cured ham.In this study,41 yeast isolates from the dry-cured ham at different processing stages were evaluated for their technological properties.Debaryomyces...Yeasts play a critical role in the flavor formation of dry-cured ham.In this study,41 yeast isolates from the dry-cured ham at different processing stages were evaluated for their technological properties.Debaryomyces hansenii was the most dominant yeast and has been detected at each phase of dry-cured ham,followed by Candida zeylanoides which was mainly detected in salting phase.Yarrowia bubula and Yarrowia alimentaria were found at the first two-phase of dry-cured ham.All isolates of yeast showed enzymatic activities against milk protein and tributyrin,while only 4 strains displayed proteolytic activity on meat protein.Yeast strains were grown in a meat model medium and volatile compounds were identified.The result showed that inoculated yeast strains could promote the production of volatiles and there were significant differences among strains.D.hansenii S25 showed the highest production of volatile compounds,followed by the strain C.zeylanoides C4.D.hansenii S25 was the highest producer of alcohols showing the highest production of benzeneethanol and 3-(methylthio)-1-propanol.Based on OAV and PLS analysis,D.hansenii S25 was strongly correlated with overall flavor and key volatile compounds of dry-cured ham,which could be selected as potential starter cultures.展开更多
LeSPL-CNR is a crucial transcription factor for fruit ripening of Solanum lycopersicum. The cnr (colorless non-ripening) epimutation resulted from hypermethylation in a 286 bp region of LeSPL-CNR promoter inhibits nor...LeSPL-CNR is a crucial transcription factor for fruit ripening of Solanum lycopersicum. The cnr (colorless non-ripening) epimutation resulted from hypermethylation in a 286 bp region of LeSPL-CNR promoter inhibits normal fruit ripening. In present study, potential regulators of LeSPL-CNR, which could bind to the specific 286 bp region, were screened via south-western blotting and yeast one-hybrid (Y1H) library screening system. Results indicated that a total of 13 and 19 candidate proteins were acquired respectively, and both ribulose-1,5-bisphosphate carboxylase/oxygenase and 40S ribosomal protein were identified by two methods. These would provide some information for revealing roles of DNA methylation and the regulatory mechanism for LeSPL-CNR.展开更多
Peanut(Arachis hypogaea L.)is a thermophilic crop,and low temperature leads to a significant reduction in annual yields.Despite a few cold tolerant germplasms or cultivars have been discovered and developed,molecular ...Peanut(Arachis hypogaea L.)is a thermophilic crop,and low temperature leads to a significant reduction in annual yields.Despite a few cold tolerant germplasms or cultivars have been discovered and developed,molecular mechanisms governing peanut cold tolerance is poorly understood.Identification of keys genes involved in cold tolerance is the first step to address the underlying mechanism.In this study,we isolated and characterized 157 genes with potentials to confer cold tolerance in peanut by using a yeast functional screening system.GO(Gene ontology)and KEGG(Kyoto encyclopedia of genes and genomes)enrichment analysis of these genes revealed that ribosome and photosynthesis proteins might play essential roles in peanut cold response.Transcriptome results indicated that 60 cold tolerance candidate genes were significantly induced or depressed by low temperature.qRT-PCR analysis demonstrated that several candidate genes could be also regulated by salt or drought stress.Individual overexpression of two UDP-glycosyltransferases(AhUGT2 and AhUGT268)in transgenic yeast cells could enhance their tolerance to multiple abiotic stress.In conclusion,this study advances our understanding of the mechanisms associated with the cold stress responses in peanut,and offers valuable gene resources for genetic improvement of abiotic stress tolerance in crops.展开更多
Four early lactating Holstein cows were used to study the effect of live yeast (LY, Actisaf®CNCM I-4407, Lesaffre Feed Additives, Marcq en Baroeul, France) supplementation on diet digestive utilization of dair...Four early lactating Holstein cows were used to study the effect of live yeast (LY, Actisaf®CNCM I-4407, Lesaffre Feed Additives, Marcq en Baroeul, France) supplementation on diet digestive utilization of dairy cows receiving concentrated corn silage-based diets with two rumen-degradable protein (RDP) levels. For a 33 d period, cows were fed a total mixed ration (TMR) containing an adequate level (AL) of RDP or a low level (LL, 30% below AL) by using soybean meal or tanned soybean meal, respectively: for 21 d with no LY addition followed by 12 d during which LY was added to the diet. The pH and redox potential (Eh) were recorded and ruminal fluid samples were collected over 3 consecutive days. Feces were collected individually over 48 h and individual dry matter intake (DMI) was measured for determining apparent nutrient digestibility. The effective degradability of individual feed ingredients composing both diets was evaluated with nylon bags technique. Structure of the ruminal bacterial community was studied and diversity index was calculated. Digestibility of organic matter (OM) and crude protein (CP) were lower for LL than those for AL. With LY, digestibility of OM and CP was increased: +2.4 and +0.8 points, for AL, and +3.7 and +5.9 points for LL, respectively. Live yeast reduced dietary N ruminal degradation with both AL and LL. Ruminal pH and Eh were lower with AL compared to LL: 5.95 and –167 mV vs. 6.13 and –144 mV. Live yeast increased ruminal total volatile fatty acids (VFA) (+8.6%), C2 (+10%), and C4 (+35%) contents for LL and decreased that of C3 (?9.8%) for AL. Neither the structure of bacterial populations of the rumen nor the diversity index (Shannon) was altered by treatments. Those results suggested a specific interest in using LY in RDP deficient diets for early lactating cows.展开更多
文摘A plant fermentation was carried out by Yeast and Lactobacilli against single cellular algae (f-Chlorella). These materials were proved by as safe in animal safety experiment. We sought to look into changes of immune-competent cells that commonly utilized f-Chlorella including after administration of immno-suppressed animals. The effects by f-Chlorella on the regurational effect to the host were measured. Our results showed that f-Chlorella regulated the level of lymphocytes, while conventional-Chlorella worked to adjust the level of granulocytes. In our clinical study with 20 healthy volunteers, granulocyte and lymphocyte ratio was obtained as neutral in the peripheral blood. In rodents, immune-compromised host as well as normal animal were prepared with cancer chemotherapeutic agent (Mytomycin-C), and then tried to rescue the immune-competent rebel. Our observations showed that both Chlorella derivatives regulated in number and functions. The effect was more prominent in f-Chlorella than that of conventional one. We discussed the significance and mechanism of f-Chlorella on the level of leukocyte subsets in number and function. These effects were considered to bring the potential elevation of antibody secreting cell by the localized heamolysis in gel method. We also proposed an idea that exhibited tonic effects were brought via activating the complement components in the serum. Moreover, we tried to access further to the anti-oxidative activities of this f-Chlorella. This modification brought to the significant lifted up for immune competent cells and anti-oxidative activity for phagocytic cells.
基金supported by grants from the National Natural Science Foundation of China(32172340)。
文摘Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic fermentation.Such influences are imposed on yeast growth and fermentation performances including the formation of secondary metabolites.Saccharomyces cerevisiae,the main yeast responsible for fermentation,has been studied extensively regarding nitrogen impacts.On the other hand,a similar study for non-Saccharomyces yeasts,whose contributions to winemaking have gradually been acknowledged,remains to be fully explored,with a few studies being reported.This review starts by discussing nitrogen impacts on non-Saccharomyces yeast growth and fermentation kinetics in different case scenarios,then proceeds to summarize the nitrogen preferences of individual yeast strains with regulation mechanisms elucidated by recent studies.Detailed discussions on the influences on the production of volatile compounds and proposed pathways therein are made,followed by future work suggested as the final section.In summarizing the nitrogen impacts on non-Saccharomyces yeasts throughout alcoholic fermentation,this review will be helpful in obtaining a more comprehensive view on these non-conventional wine yeasts in terms of nutrient requirements and corresponding volatile production.Research gaps will therefore be elucidated for future research.
文摘The budding yeast Saccharomyces cerevisiae is a powerful model system for studying the cell polarity establishment.The cell polarization process is regulated by signaling molecules,which are initially distributed in the cytoplasm and then recruited to a proper location on the cell membrane in response to spatial cues or spontaneously.Polarization of these signaling molecules involves complex regulation,so the mathematical models become a useful tool to investigate the mechanism behind the process.In this review,we discuss how mathematical modeling has shed light on different regulations in the cell polarization.We also propose future applications for the mathematical modeling of cell polarization and morphogenesis.
文摘Sorghum beer or dolo is part of the eating habits of part of the population of Dédougou because of its low price compared with industrial beers. Its production is an ancestral tradition that uses traditional equipment and gives dolo organoleptic properties that are not found in industrial beers. The production process involves several stages, including fermentation, which itself comprises natural lactic fermentation followed by alcoholic fermentation using traditional yeasts, which are not controlled in any way. The general aim of this study is to assess the microbiological quality of these fermentative yeasts in the town of Dédougou, in order to contribute to the health safety of the population and the promotion of these local beers. Twenty samples of fermenting yeast were analyzed according to ISO standards, to isolate enterobacteria, total and faecal coliforms according to standard procedures for isolating these micro-organisms. The isolated strains were identified using the API20E gallery. Microbiological analyses revealed the presence of 51.17% enterobacteria, 45.38% total coliforms and 3.45% thermotolerant coliforms. We counted 40% Escherichia coli, 20% Enterobacter cloacae, 20% Klebsiella pneumoniae and 20% Klebsiella spp. All the strains detected are capable of surviving in hostile conditions and could harm the quality of the dolo, consumer health and cause real collective food poisoning in the town of Dédougou. This enabled us to assess the microbial quality of these yeasts and to propose more suitable measures for producing and preserving dolo under hygienic conditions to protect consumer health.
文摘Background There is a growing search for natural feed additives to alleviate the deleterious effects of coccidia infection in poultry production.This study aimed to investigate the effect of enzymatically treated yeast(ETY) on the growth performance,nutrient digestibility,intestinal morphology,antioxidative status,and cecal mucosa cytokines of coccidia-challenged broiler chickens.Methods From d 1 to 14 post hatching,480 broiler chickens were allocated to 3 corn-soybean meal-based experimental diets with increasing concentrations of ETY(0,1,or 2 g/kg).The experiment was designed as a randomized complete block design with body weight(BW) used as a blocking factor.On d 14 post hatching,the birds were re-randomized within each of the 3 experimental diets.Each of the 3 diet groups was split into a challenge or no-challenge group.This resulted in a 3 × 2 factorial arrangement of treatments.The coccidia challenge was administered on d 15 by an oral gavage.Results Dietary ETY improved(P < 0.05) the G:F of birds on d 21 regardless of the challenge state and linearly increased(P < 0.01) the apparent ileal digestibility of dry matter(DM),nitrogen,and gross energy(GE).The coccidia challenge decreased(P < 0.05) BW gain and feed intake of broiler chickens and reduced(P < 0.01) the total tract retention of DM,GE,and nitrogen.The coccidia challenge increased(P < 0.01) the mRNA gene expression of TNFα,IL-1β,IL-10,and IL-6 in the cecal mucosa.There was a tendency(P ne = 0.08) for ETY to linearly reduce IL-1β expression.Additionally,ETY supplementation increased(P < 0.05) the geexpression of OCLN.Serum catalase increased(P < 0.05) with dietary ETY in broiler chickens on d 21.Dietary ETY linearly increased(P < 0.05) the ileal villus height to crypt depth ratio,and ileal goblet cell density in broiler chickens.The ileal and excreta oocyst counts decreased(P < 0.01) with increasing supplementation of dietary ETY in coccidia-challenged broiler chickens on d 21.Conclusions Dietary ETY enhanced nutrient utilization and augmented intestinal development in broiler chickens.However,dietary ETY did not completely attenuate the adverse effects of a coccidia challenge in broiler chickens.
文摘Micro-environmental restriction effects to yeast cell growth obtained within Ca-alginate microbeads are considered. It is complex phenomenon influenced by: (1) relaxation of expanded polymer network around the cellular clusters, (2) forces generated by cell growth inside the beads and (3) interactions between solvent, network parts and cells. The resulting effects are measured experimentally by estimating volume of microbeads and yeast cell concentration as function of time of cultivation. Comparative analysis of dynamics of cell growth and increase of microbead volume through four regimes indicates that reversible and irreversible local structural changes of Ca-alginate hydrogel induces micro-environmental restrictions to cell growth. The mechanism of restrictions includes both mechanical and electrostatic effects.
文摘Pectinases are used in Enology for some different utilities. Enzymatic preparations from moulds are a mixed of different enzymes with strong and unspe-cific activities. Some Saccharomyces cerevisiae pro-duce pectinases which can be used instead of com-mercial preparations. The objectives of this work were to study the enzyme secretion by one Saccharo-myces cerevisiae (CECT 11783) for growing on grape skin (industry oenological by-product) as carbon source. Preliminary experiments showed that the strain produced pectinases for growing on grape skin without any other carbon source. Statistical treat-ment (factorial design 25) was applied to evaluate the influences of related factors (agitation, temperature, presence of peptone and detergent in the medium and time of growth) Variables with the most significant interactions for pectinase production were agitation and nitrogen source concentration. Response surface methodology showed that a first order model was not adequate for results. Nevertheless, the built of a sec-ond order model offered a polynomial equation which surface predicted a maximum of activity (52.68 enzymatic units) for specific values of the studied variables (147.8 rpm of agitation and 15.9 g of pep-tone/ L culture medium).
文摘Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of the Smc1-Smc3-Scc1 cohesin ring, is phosphorylated on S/T-Q residues. This event depended on the Mec1 checkpoint kinase as well as on cell cycle arrest triggered by the DNA damage checkpoint network. This phosphorylation event also took place during mitosis of an unperturbed cell cycle. The present finding that S. cerevisiae Scc3 is phosphorylated during mitosis represents a potentially important new regulatory step in cohesin’s mitotic functions.
文摘Ethyl caproate and isoamyl alcohol are important for the quality of Yakju, one of the Korean traditional alcoholic beverages. From Korean traditional fermentation agent, Nuruk, we have isolated 8 yeasts which produced rich aromatic compounds using YEPD agar plates (1% yeast extract, 2% peptone, 2% dextrose, 2% agar) containing 50 uL cerulenin at 30℃. The isolated aromatic yeasts are identified as Pichia anomala (4 strains), Pichia fabianii (2 strains), Pichia farinose (1 strains), Geotrichum candidum (1 strains). We conducted alcohol fermentation with each of the aromatic yeasts and the compounds (ethyl caproate and isoamyl alcohol) producing range were 59.5 - 193.2 ppm and 10.8 - 91.6 ppm respectively. As a control, Fermivin®, famous aromatic wine yeast, was 89.4 ppm and 16.2 ppm respectively. We also find that the isolated Pichia anomala could produce higher level ethanol (4.2% - 5.0%, v/v) than other species (0.4% - 2.2%, v/v). Using the aromatic yeasts in fermentation industries, we expect to improve the quality of traditional alcoholic beverages.
基金Supported by Heilongjiang Natural Science Foundation Joint Guide Project(LH2019C022)。
文摘Higher levels of acetaldehyde in beer are one of the major concerns in the current beer industry.Yeast produces acetaldehyde during alcoholic fermentation,and its modification significantly affects beer flavor and quality.A different mutant strain with lower acetaldehyde production and improved ethanol tolerance was constructed using the ARTP-ALE mutagenesis strategy with 4-methylpyrazole-disulfiram.As a result of the mutation,the alcohol dehydrogenase activity of the mutant strain decreased to about 71.22%of that of the wild-type strain.At the same time,the fermentation properties and genetic stability of the newly screened strain showed slight differences from the wild-type strain,and there were no safety concerns regarding industrial use of the mutant strain.
文摘The yeast MATα1 is required for the activation of α-specific genes in Saccharomyces cerevisiae and thus confers the α-cell identity of the yeast. MATα1 contains a domain called the α-domain which has significant sequence identity to the HMG-box family of proteins. A multiple sequence alignment of several α-domains and various structurally determined HMG-box domains has revealed that both domains possess very similar structural and functional residues. We found that the basic amino acids of the N-terminal loop, the intercalating hydrophobic residues of the first helix, and the hydrophobic residues required for interactions within the core of the protein are remarkably conserved in α-domains and HMG-box proteins. Our generated molecular models suggest that the first and third helix will be shorter and that the HMG-box core is not an isolated domain. The region beyond the conserved HMG-box motif contains an extended helical region for about 20 - 30 amino acids. Structural models generated by comparative modeling and ab initio modeling reveal that this region will add two or more additional α-helices and will make significant contacts to helix III, II and I of the HMG-box core. We were able to illustrate how the extended α-domain would bind to DNA by merging of the α-domain and the LEF-1/DNA complex. The models we are reporting will be helpful in understanding how MATα1 binds to DNA with its partner MCM1 and activates transcription of α-specific genes. These models will also aid in future biophysical studies of MATα1 including the crystallization and structure determination.
文摘Purpose: In a placebo-controlled, double-blind, randomized clinical trial, the effect of an insoluble yeast beta-glucan preparation on the incidences of common colds and its effect on common cold symptoms were compared to placebo. Methods: 100 healthy participants with recurring infections were randomly assigned to receive either placebo or yeast beta-glucan (Yestimun?;n = 50 each group) over a period of 26 weeks. The subjects had to document each common cold episode in a diary, and rate 6 predefined infections symptoms on a 3-point rating scale during an infection period, resulting in an infection score. The common cold episodes were confirmed by the investigators. Results: A total of 171 common cold episodes were documented. Of these, 76 were experienced by 38 subjects in the beta-glucan group and 96 were experienced by 48 subjects in the placebo group (p = 0.406). The beta-glucan group had significantly more subjects without incidences of common cold than the placebo group (15.6% vs 2.0%;p = 0.019). During the most intense infection season (first 13 weeks of the study), the beta-glucan group had significantly less infections compared to placebo (p = 0.02). Beta-glucan significantly reduced the typical cold symptoms (“sore throat and/or difficulty swallowing”, “hoarseness and/or cough” and “runny nose”) as opposed to placebo. Conclusion: The present study demonstrates a prophylactic effect of yeast beta-glucan on the occurrence of common colds as opposed to placebo. In addition, when these episodes occurred, they were from the beginning less pronounced and subsided faster.
文摘For practical applications of bioethanol, the uses of both highly concentrated biomass materials and their effective fermentation by yeasts are indispensable in order to produce ethanol at low costs. However, as the saccharified products of those biomass generally contain abundant sugars, the yeasts are affected by the compounds and are inclined to decrease their physiological activities. In the process of fermentation, ethanol is gradually produced by the yeasts in the culture;the concentrated metabolic product also damages itself, and inhibition of the fermentation frequently occurs. The application of yeasts with high fermentative activities under stress pressures such as sugars and ethanol is thus desired for bioethanol production. In this study, various types of high-fermentative yeasts under stress pressures were isolated mainly from coastal waters in Japan and characterized. All yeast strains with high fermentative activities under 20% v/v ethanol were found to be Saccharomyces cerevisiae. The HK21 strain isolated from Tokyo Bay and identified as S. cerevisiae had the highest fermentation activity under 30% w/v sorbitol and under 20% v/v ethanol, and it produced approx. 70 g/l (9% v/v) ethanol from the 15% w/v glucose solution at 25 oC within 5 days.
基金supported by the National Key Research and Development Program of China(2018YFD0500605)the Key Research and Development Program of Sichuan Province(2021YFYZ0008)the Sichuan Pig Innovation Team of National Modern Agricultural Industry Technology System of China(scsztd-2020-08-11)。
文摘Background Intestinal inflammation is the main risk factor causing intestinal barrier dysfunction and lipopolysaccharide(LPS)can trigger inflammatory responses in various eukaryotic species.Yeast hydrolysate(YH)possesses multibiological effects and is received remarkable attention as a functional ingredient for improving growth performance and promoting health in animals.However,there is still inconclusive on the protective effects of dietary YH supplementation on intestinal barrier of piglets.This study was conducted to investigate the attenuate effects of YH supplementation on inflammatory responses and intestinal barrier injury in piglets challenged with LPS.Methods Twenty-four piglets(with an average body weight of 7.42±0.34 kg)weaned at 21 days of age were randomly assigned to one of two dietary treatments(12 replications with one pig per pen):a basal diet or a basal diet containing YH(5 g/kg).On the 22nd d,6 piglets in each treatment were intraperitoneally injected with LPS at 150μg/kg BW,and the others were injected with the same amount of sterile normal saline.Four hours later,blood samples of each piglet were collected and then piglets were euthanized.Results Dietary YH supplementation increased average daily feed intake and average daily gain(P<0.01),decreased the ratio of feed intake to gain of piglets(P sponse,evidenced by the increase o=0.048).Lipopolysaccharide(LPS)injection induced systemic inflammatory ref serum concentrations of haptoglobin(HP),adrenocorticotropic hormone(ACTH),cortisol,and interleukin-1β(IL-1β).Furthermore,LPS challenge resulted in inflammatory intestinal damage,by up-regulation of the protein or mRNA abundances of tumor necrosis factor-α(TNF-α),IL-1β,toll-like receptors 4(TLR4)and phosphor-nuclear factor-κB-p65(p-NFκB-p65)(P<0.01),and down-regulation of the jejunal villus height,the protein and mRNA abundances of zonula occludens-1(ZO-1)and occludin(OCC;P<0.05)in jejunal mucosa.Dietary YH supplementation decreased the impaired effects of ACTH,cortisol,HP,IL-1βand diamine oxidase in serum(P<0.05).Moreover,YH supplementation also up-regulated the jejunal villus height,protein and mRNA abundances of ZO-1 and OCC(P<0.05),down-regulated the mRNA expressions of TNF-αand IL-1βand the protein abundances of TNF-α,IL-1β,TLR4 and p-NFκB-p65 in jejunal mucosa in LPS-challenged pigs(P<0.01).Conclusion Yeast hydrolysate could attenuate inflammatory response and intestinal barrier injury in weaned piglets challenged with LPS,which was associated with the inhibition of TLR4/NF-κB signaling pathway activation.
基金the financial support of Guizhou Province Science and Technology Plan Project(QKHZC[2020]1Y152)the Guizhou High-level Innovative Talent Training Project(Qianke Cooperation Platform Talent number[2016]5662)Guizhou Science and Technology Innovation Talent Team of Ecological Characteristic Meat Products(QKHPTRC[2020]5004).
文摘Yeasts play a critical role in the flavor formation of dry-cured ham.In this study,41 yeast isolates from the dry-cured ham at different processing stages were evaluated for their technological properties.Debaryomyces hansenii was the most dominant yeast and has been detected at each phase of dry-cured ham,followed by Candida zeylanoides which was mainly detected in salting phase.Yarrowia bubula and Yarrowia alimentaria were found at the first two-phase of dry-cured ham.All isolates of yeast showed enzymatic activities against milk protein and tributyrin,while only 4 strains displayed proteolytic activity on meat protein.Yeast strains were grown in a meat model medium and volatile compounds were identified.The result showed that inoculated yeast strains could promote the production of volatiles and there were significant differences among strains.D.hansenii S25 showed the highest production of volatile compounds,followed by the strain C.zeylanoides C4.D.hansenii S25 was the highest producer of alcohols showing the highest production of benzeneethanol and 3-(methylthio)-1-propanol.Based on OAV and PLS analysis,D.hansenii S25 was strongly correlated with overall flavor and key volatile compounds of dry-cured ham,which could be selected as potential starter cultures.
文摘LeSPL-CNR is a crucial transcription factor for fruit ripening of Solanum lycopersicum. The cnr (colorless non-ripening) epimutation resulted from hypermethylation in a 286 bp region of LeSPL-CNR promoter inhibits normal fruit ripening. In present study, potential regulators of LeSPL-CNR, which could bind to the specific 286 bp region, were screened via south-western blotting and yeast one-hybrid (Y1H) library screening system. Results indicated that a total of 13 and 19 candidate proteins were acquired respectively, and both ribulose-1,5-bisphosphate carboxylase/oxygenase and 40S ribosomal protein were identified by two methods. These would provide some information for revealing roles of DNA methylation and the regulatory mechanism for LeSPL-CNR.
基金This work was supported by a grant from the National Natural Science Foundation of China(No.32170278)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(No.CAAS-ASTIP-2021-OCRI)the Earmarked fund for China Agricultural Research System(CARS-13).
文摘Peanut(Arachis hypogaea L.)is a thermophilic crop,and low temperature leads to a significant reduction in annual yields.Despite a few cold tolerant germplasms or cultivars have been discovered and developed,molecular mechanisms governing peanut cold tolerance is poorly understood.Identification of keys genes involved in cold tolerance is the first step to address the underlying mechanism.In this study,we isolated and characterized 157 genes with potentials to confer cold tolerance in peanut by using a yeast functional screening system.GO(Gene ontology)and KEGG(Kyoto encyclopedia of genes and genomes)enrichment analysis of these genes revealed that ribosome and photosynthesis proteins might play essential roles in peanut cold response.Transcriptome results indicated that 60 cold tolerance candidate genes were significantly induced or depressed by low temperature.qRT-PCR analysis demonstrated that several candidate genes could be also regulated by salt or drought stress.Individual overexpression of two UDP-glycosyltransferases(AhUGT2 and AhUGT268)in transgenic yeast cells could enhance their tolerance to multiple abiotic stress.In conclusion,this study advances our understanding of the mechanisms associated with the cold stress responses in peanut,and offers valuable gene resources for genetic improvement of abiotic stress tolerance in crops.
文摘Four early lactating Holstein cows were used to study the effect of live yeast (LY, Actisaf®CNCM I-4407, Lesaffre Feed Additives, Marcq en Baroeul, France) supplementation on diet digestive utilization of dairy cows receiving concentrated corn silage-based diets with two rumen-degradable protein (RDP) levels. For a 33 d period, cows were fed a total mixed ration (TMR) containing an adequate level (AL) of RDP or a low level (LL, 30% below AL) by using soybean meal or tanned soybean meal, respectively: for 21 d with no LY addition followed by 12 d during which LY was added to the diet. The pH and redox potential (Eh) were recorded and ruminal fluid samples were collected over 3 consecutive days. Feces were collected individually over 48 h and individual dry matter intake (DMI) was measured for determining apparent nutrient digestibility. The effective degradability of individual feed ingredients composing both diets was evaluated with nylon bags technique. Structure of the ruminal bacterial community was studied and diversity index was calculated. Digestibility of organic matter (OM) and crude protein (CP) were lower for LL than those for AL. With LY, digestibility of OM and CP was increased: +2.4 and +0.8 points, for AL, and +3.7 and +5.9 points for LL, respectively. Live yeast reduced dietary N ruminal degradation with both AL and LL. Ruminal pH and Eh were lower with AL compared to LL: 5.95 and –167 mV vs. 6.13 and –144 mV. Live yeast increased ruminal total volatile fatty acids (VFA) (+8.6%), C2 (+10%), and C4 (+35%) contents for LL and decreased that of C3 (?9.8%) for AL. Neither the structure of bacterial populations of the rumen nor the diversity index (Shannon) was altered by treatments. Those results suggested a specific interest in using LY in RDP deficient diets for early lactating cows.