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1.
Food Chem ; 313: 126129, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31935665

RESUMO

Thymoquinone is a chief phytochemical constituent of black cumin seed oil (BCSO) and shows strong bioactivity. It has a weak stability against environmental conditions like heat and light. Encapsulation process by Saccharomyces cerevisiae is a popular technique to preserve the bioactivity and increase the stability of functional bioactive compounds. In the current study, BCSO was encapsulated by both plasmolysed (PYC) and nonplasmolysed yeast cell (NPYC) and stability of thymoquinone and bioactive properties of all samples were evaluated. And also, some physicochemical, morphological and conformational characterizations were carried out for the encapsules. The results showed that thymoquinone concentration and its bioactivity were preserved better in PYC during storage compared to BCSO and NPYC. The highest degradation ratio of thymoquinone during storage for the BCSO was 96.78% while the lowest one was for the PYC sample (52.63%).


Assuntos
Benzoquinonas/química , Cápsulas/química , Nigella sativa/metabolismo , Óleos Vegetais/química , Saccharomyces cerevisiae/química , Benzoquinonas/metabolismo , Depuradores de Radicais Livres/química , Nigella sativa/química , Sementes/química , Sementes/metabolismo
2.
J Agric Food Chem ; 68(1): 267-278, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31833769

RESUMO

Gas chromatography-olfactometry coupled with sensory analysis and partial least-squares regression (PLSR) analysis led to the identification of the odorants responsible for the different flavors of four yeast extracts. Sensory analysis showed that LA00L had an intense sulfurous attribute, and LA00 was characterized by fatty and green notes, FA31 exhibited the floral odor, while KA02 had strong phenolic, animal, fermented, roasted, and caramellic notes. A total of 37 key aroma compounds with odor activity values greater than 1 were determined. 2,4-Di-tert-butylphenol and methional were the most potent aroma compounds. In addition, the key aroma compounds in LA00L were nonanal, dimethyl disulfide, and γ-decalactone. Octanal, dimethyl disulfide, and benzeneacetaldehyde were the key aroma compounds in LA00. In FA31, styrene, benzeneacetaldehyde, and acetophenone were the key aroma compounds, while indole, 2-methoxyphenol, benzeneacetaldehyde, and p-cresol contributed significantly to the aroma of KA02. PLSR showed that p-cresol and indole were significantly responsible for the phenolic and animal notes inducing the off-flavor (yeasty odor) of yeasty extracts. More significantly, indole was first reported to have an important effect on yeasty odor.


Assuntos
Aromatizantes/química , Odorantes/análise , Saccharomyces cerevisiae/química , Compostos Orgânicos Voláteis/química , Adulto , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Pessoa de Meia-Idade , Olfato , Adulto Jovem
3.
Food Chem ; 309: 125700, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31685371

RESUMO

This study evaluates the role of intracellular composition and integrity of cell walls in modulating the release and bioaccessibility of phytochemicals during simulated gastrointestinal digestion of cell-based carriers. Native yeast and yeast cell wall particles (YCWPs) were used as model cell-based carriers with distinct intracellular composition and curcumin was a model encapsulated bioactive. The results highlight the essential role of gastric treatments and the presence of bile salts in the release and bioaccessibility of encapsulated compound from cell-based carriers. YCWPs with significantly reduced intracellular contents have a significantly faster intestinal release after gastric digestion. Multimodal imaging approaches confirm the release of encapsulated curcumin in intestinal compartment without any significant changes in the cellular structure including cell walls. Based on these results, the study proposes a model that illustrate the significance of gastric digestion in influencing the release of curcumin during gastrointestinal digestion.


Assuntos
Parede Celular/química , Curcumina/química , Saccharomyces cerevisiae/química , Disponibilidade Biológica , Curcumina/metabolismo , Digestão , Humanos , Microscopia Confocal
4.
Food Microbiol ; 86: 103339, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703886

RESUMO

The study of microbial communities associated with spontaneous fermentation of agave juice for tequila production is required to develop starter cultures that improve both yield and quality of the final product. Quantification by HPLC of primary metabolites produced during the fermentations was determined. A polyphasic approach using plate count, isolation and identification of microorganisms, denaturing gradient gel electrophoresis and next generation sequencing was carried out to describe the diversity and dynamics of yeasts and bacteria during small-scale spontaneous fermentations of agave juice from two-year samplings. High heterogeneity in microbial populations and fermentation parameters were observed, with bacteria showing higher diversity than yeast. The core microorganisms identified were Saccharomyces cerevisiae and Lactobacillus fermentum. Practices in tequila production changed during the two-year period, which affected microbial community structure and the time to end fermentation. Bacterial growth and concomitant lactic acid production were associated with low ethanol production, thus bacteria could be defined as contaminants in tequila fermentation and efforts to control them should be implemented.


Assuntos
Bebidas Alcoólicas/microbiologia , Bactérias/metabolismo , Leveduras/isolamento & purificação , Agave/química , Agave/microbiologia , Bebidas Alcoólicas/análise , Bactérias/química , Bactérias/genética , Bactérias/isolamento & purificação , Biodiversidade , Etanol/metabolismo , Fermentação , Cinética , Lactobacillus fermentum/química , Lactobacillus fermentum/metabolismo , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Leveduras/química , Leveduras/genética , Leveduras/metabolismo
5.
Ecotoxicol Environ Saf ; 187: 109712, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31654867

RESUMO

Mycotoxicosis is the second most important problem faced by the Pakistan poultry industry, after high feed prices. The present experimental study was designed to investigate the toxicopathological effects of aflatoxin B1 (AFB1) in commercial broiler chicks and its amelioration with locally produced mycotoxin binder. Total of 125 broiler chicks was divided into five equal groups (A-E). Group A served as negative control, group B (300 µg AFB1/kg feed) as positive control, group C (300 µg AFB1/kg + Local Mycotoxin Binder (LMB), 1 g/kg feed), group D (300 µg AFB1/kg + 2 g LMB/kg feed), and group E (300 µg AFB1/kg + Commercial Mycotoxin Binder (CMB), 2 g/kg of feed). Parameters studied included mortality, feed intake, bodyweights, absolute and relative organ weights, and gross and microscopic lesions in visceral organs. Clinical signs including alertness, fecal consistency, and feather shine were significantly lower in group B compared with control group A. The feed intake of 2 g/kg LMB treated group was significantly higher than that of the positive control group B. Also mean bodyweights of group D birds was higher than that of group B birds indicating an ameliorative effect of LMB. Histopathological results showed that moldy feed produced necrotic changes in the liver and kidneys in group B birds. However, in group D and E birds, the hepatic and renal parenchyma was normal, showing a protective effect of LMB. In the present study, a higher dose of LMB (2 g/kg) in group D showed higher bodyweights and feed intake. In group D, birds hepatic and renal parenchyma was also normal. The results suggested that local mycotoxin binder ameliorated the toxicopathological effects of AFB1 in mortality, feed intake, bodyweights, organ weights and, gross and microscopic lesions in visceral organs. These ameliorative effects of LMB were dose-dependent. The results of the present study concluded that AFB1 intoxication leads to decrease in bodyweights, feed intake in dose-related manner. The mortality was also dose-dependent. Gross and microscopic changes in the aflatoxin groups were more pronounced, however, all these deleterious effects were ameliorated in higher dose of LMB (group D) and CMB (group E). In group C, these deleterious effects were partially ameliorated. Local mycotoxin binder is an economical solution for aflatoxicosis problem, making poultry production more cost-effective.


Assuntos
Aflatoxina B1/toxicidade , Ração Animal/análise , Contaminação de Alimentos/prevenção & controle , Micotoxicose/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Aflatoxina B1/química , Animais , Bentonita/administração & dosagem , Bentonita/química , Galinhas , Contaminação de Alimentos/análise , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Micotoxicose/veterinária , Tamanho do Órgão , Paquistão , Saccharomyces cerevisiae/química
6.
Ecotoxicol Environ Saf ; 187: 109765, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31670239

RESUMO

A novel polyvinyl alcohol/carboxymethyl cellulose/yeast double degradable hydrogel was prepared with yeast as a foaming agent. The chemical structure of the hydrogel was characterized by FTIR and XPS. The micro-structure of the hydrogel was observed by SEM. The specific surface area and pore size of hydrogel were measured by BET. Methylene blue adsorption capacity of the hydrogels were investigated and the adsorption mechanism was explored. The biodegradability of double degradable hydrogel was investigated. The results showed that yeast was encapsulated in hydrogel by electrostatic action. With the addition of yeast, not only the specific surface area and average pore size of the hydrogel increased but also methylene blue maximum adsorption capacity of the double degradable hydrogel (110 ±â€¯3.5 mg/g) was significantly higher than that of the hydrogel without yeast (57 ±â€¯1.9 mg/g). The adsorption mechanism was dominated by chemical adsorption and was accompanied by biodegradable and electrostatic adsorption. The kinetic data were fitted to the pseudo-second-order kinetic model reasonably well. The introduction of yeast promoted the biodegradable of hydrogel and increased the degradation rate of polyvinyl alcohol in the material with a maximum degradation rate of 45 ±â€¯2.8%.


Assuntos
Carboximetilcelulose Sódica/química , Hidrogéis/química , Azul de Metileno/análise , Álcool de Polivinil/química , Saccharomyces cerevisiae/química , Poluentes Químicos da Água/análise , Adsorção , Biodegradação Ambiental , Cinética , Modelos Teóricos , Porosidade , Saccharomyces cerevisiae/metabolismo , Propriedades de Superfície , Purificação da Água/métodos
7.
J Enzyme Inhib Med Chem ; 35(1): 129-137, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31694426

RESUMO

The 3-hydroxy-3-methylglutaryl-CoA reductase, a key enzyme of the mevalonate pathway for the synthesis of cholesterol in mammals (ergosterol in fungi), is inhibited by statins, a class of cholesterol lowering drugs. Indeed, statins are in a wide medical use, yet statins treatment could induce side effects as hepatotoxicity and myopathy in patients. We used Saccharomyces cerevisiae as a model to investigate the effects of statins on mitochondria. We demonstrate that statins are active in S.cerevisiae by lowering the ergosterol content in cells and interfering with the attachment of mitochondrial DNA to the inner mitochondrial membrane. Experiments on murine myoblasts confirmed these results in mammals. We propose that the instability of mitochondrial DNA is an early indirect target of statins.


Assuntos
DNA Mitocondrial/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/metabolismo , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Saccharomyces cerevisiae/química , DNA Mitocondrial/química , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Membranas Mitocondriais/química
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117389, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31377683

RESUMO

Rational design chelating fluorescent sensors probing metal ions in biological system are continuously hot essays nowadays, especially for zinc detection. Herein, a naphthylideneimine based zinc fluorescence probe (3) was prepared and characterized in this work. Structural features and optical properties of 3 and its metallic complexes were characterized. Fluorescent experiment indicates 3 is extremely sensitive and selective for Zn2+ with a strong fluorescence enhancement (∼34 folds) in aqueous buffer solution with a limit of detection (LOD) of 3.78 × 10-7 mol L-1. Formation constant (logKa) of the chelating complex of 3 and Zn2+ ion was determined to be 4.45. Theoretical studies were carried out to get deep insight into the response mechanism in the sensing process. Density functional theory (DFT) methods calculated formation Gibbs free energy (ΔrGmÓ©) of the deprotonated complexes model (32- ⊃ Zn) is -2.9 kcal/mol, which is in good agreement with the experimental result. The calculation results show that the low excitation states can be ascribe to S0 → T2 and S0 → S1 at 390-430 nm and 310-330 nm, respectively, due to the π → π∗ transition. Finally, yeast cell imaging experiments indicate that 3 can monitor intracellular Zn2+ as well. These findings would enable this fluorescent probe to be used as a Zinc sensor.


Assuntos
Corantes Fluorescentes/química , Naftalenos/química , Bases de Schiff/química , Espectrometria de Fluorescência/métodos , Zinco/análise , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/química
9.
Chemosphere ; 239: 124768, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518917

RESUMO

There is a need for cheap but, efficient methods for the removal of precious metals from wastewaters, which are normally lost during mineral processing. Moreover, the disposal of yeast waste from brewing has been a problem in many parts of the world. In this study, the removal of Pt(IV) from aqueous solutions using the readily available bentonite clay functionalised with spent yeast from brewing was investigated. The maximum adsorption capacity of Pt(IV) with 100 mg yeast-functionalised bentonite at pH 2 within 90 min was 255 µg g-1 (98.5% efficiency) but, decreased as pH increased. The adsorption capacity of Pt(IV) was insignificantly (p > 0.05) affected by the presence of competing ions (Fe(III), Ca(II), Mg(II), K(I), Co(II), Ni(II), Hf(IV), Zn(II) and other platinum group metals (PGMs)). Moreover, most of these metals were significantly adsorbed along with Pt(IV). The indicative cost-benefit analysis showed that 1 kg of the yeast-functionalised bentonite can remove ∼700 g Pt(IV) in which a profit of more than USD20000 can be made. The bentonite functionalised with spent yeast from brewing has a potential to recover lost PGMs in wastewater. Since, this is a cheap process, the mining and other industries can make much profit from such recoveries.


Assuntos
Bentonita/química , Platina/isolamento & purificação , Saccharomyces cerevisiae/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Resíduos Industriais , Metais/química , Soluções , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias , Água/química
10.
An Acad Bras Cienc ; 91(4): e20180169, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31721914

RESUMO

This study aimed to evaluate the effect of the commercial probiotic (Saccharomyces cerevisiae), antibiotic (florfenicol), and its combination for Nile tilapia culture. The experiment was arranged in a completely randomized design with five replications, and five treatments diets: Control: water and diet without additives; YD: yeast in the diet (1 g Kg-1); AW: antibiotic in the water (0.002 g L-1); AWYD: antibiotic in the water, and yeast in the diet (0.002 g L-1 and 1 g Kg-1); and AD: antibiotic in the diet (0.01 g kg-1). The growth parameters as total and standard length, weight, weight gain, biomass, Fulton's condition factor, specific growth rate and plasma cortisol of tilapia did not show the difference between the treatments. The survival rates and food conversion rate of fish were greater in treatment with florfenicol included in the diet. The commercial probiotic did not improve growth or survival. The administration of the antibiotic florfenicol in the water needs more studies. The inclusion of the antibiotic in the diet promotes growth and survival in Nile tilapia juvenile.


Assuntos
Ração Animal , Antibacterianos/administração & dosagem , Ciclídeos/crescimento & desenvolvimento , Probióticos/administração & dosagem , Saccharomyces cerevisiae/química , Tianfenicol/análogos & derivados , Animais , Aquicultura , Tianfenicol/administração & dosagem
11.
Nat Struct Mol Biol ; 26(12): 1158-1166, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31740857

RESUMO

Nearly all mitochondrial proteins are encoded by the nuclear genome and imported into mitochondria after synthesis on cytosolic ribosomes. These precursor proteins are translocated into mitochondria by the TOM complex, a protein-conducting channel in the mitochondrial outer membrane. We have determined high-resolution cryo-EM structures of the core TOM complex from Saccharomyces cerevisiae in dimeric and tetrameric forms. Dimeric TOM consists of two copies each of five proteins arranged in two-fold symmetry: pore-forming ß-barrel protein Tom40 and four auxiliary α-helical transmembrane proteins. The pore of each Tom40 has an overall negatively charged inner surface attributed to multiple functionally important acidic patches. The tetrameric complex is essentially a dimer of dimeric TOM, which may be capable of forming higher-order oligomers. Our study reveals the detailed molecular organization of the TOM complex and provides new insights about the mechanism of protein translocation into mitochondria.


Assuntos
Proteínas de Transporte/química , Proteínas de Transporte da Membrana Mitocondrial/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/química , Proteínas de Transporte/metabolismo , Proteínas de Transporte/ultraestrutura , Microscopia Crioeletrônica , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/ultraestrutura , Modelos Moleculares , Conformação Proteica , Multimerização Proteica , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Transporte Proteico , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/ultraestrutura
12.
Nat Struct Mol Biol ; 26(10): 955-962, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31582849

RESUMO

DNA polymerase δ (Polδ) plays pivotal roles in eukaryotic DNA replication and repair. Polδ is conserved from yeast to humans, and mutations in human Polδ have been implicated in various cancers. Saccharomyces cerevisiae Polδ consists of catalytic Pol3 and the regulatory Pol31 and Pol32 subunits. Here, we present the near atomic resolution (3.2 Å) cryo-EM structure of yeast Polδ holoenzyme in the act of DNA synthesis. The structure reveals an unexpected arrangement in which the regulatory subunits (Pol31 and Pol32) lie next to the exonuclease domain of Pol3 but do not engage the DNA. The Pol3 C-terminal domain contains a 4Fe-4S cluster and emerges as the keystone of Polδ assembly. We also show that the catalytic and regulatory subunits rotate relative to each other and that this is an intrinsic feature of the Polδ architecture. Collectively, the structure provides a framework for understanding DNA transactions at the replication fork.


Assuntos
DNA Polimerase III/química , DNA Polimerase Dirigida por DNA/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/química , Sequência de Aminoácidos , Microscopia Crioeletrônica , DNA Polimerase III/metabolismo , DNA Polimerase III/ultraestrutura , DNA Fúngico/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , DNA Polimerase Dirigida por DNA/ultraestrutura , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/ultraestrutura , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/ultraestrutura
13.
Chem Asian J ; 14(24): 4760-4766, 2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31647188

RESUMO

Fluorescent nucleic acid base mimics serve as excellent site-specific and real-time reporters of the local and global dynamics. In this work, using the fluorescent guanine mimic 6-methylisoxanthopterin (6-MI), we unravel the differential dynamics of replication fork barrier/terminator sequences (RFB1 and RFB3) mediated by fork blocking protein (Fob1). By strategic and site-specific incorporation of this probe, we show that 6-MI is able to capture the changes in global dynamics exhibited by Fob1 and aids in distinguishing between varied architectural forms like double-stranded DNA versus Holliday junctions (HJs). This is important as these barriers are hotspots for recombination. Fluorescence lifetime and anisotropy decay studies further revealed that Fob1 strongly dampens the dynamics in double-stranded RFB1, and the sequence inherently possesses lesser flexibility in comparison to RFB3. We show that 6-MI can probe the differential oligomeric status of Fob1 in response to various architectures, that is, double-stranded versus HJs. This work highlights the unique advantages of 6-MI as a probe when incorporated in nucleic acid frameworks.


Assuntos
Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Corantes Fluorescentes/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Xantopterina/análogos & derivados , DNA/genética , Replicação do DNA , DNA Cruciforme , Proteínas de Ligação a DNA/genética , Escherichia coli/genética , Ligação Proteica , Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Xantopterina/química
14.
Molecules ; 24(20)2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31614997

RESUMO

Fermentation in solid state culture (SSC) has been the focus of increasing interest because of its potential for industrial applications. In previous studies SSC of pomegranate wastes by Aspergillus niger has been extensively developed and optimized for the recovery of ellagic acid (EA), a high value bioactive. In this study we comparatively investigated the SSC of powdered pomegranate husks by A. niger and Saccharomyces cerevisiae and evaluated the recovery yields of EA by an ultrasound and microwave-assisted 7:3 water/ethanol extraction. Surprisingly enough, the yields obtained by S. cerevisiae fermentation (4% w/w) were found 5-fold higher than those of the A. niger fermented material, with a 10-fold increase with respect to the unfermented material. The EA origin was traced by HPLC analysis that showed a significant decrease in the levels of punicalagin isomers and granatin B and formation of punicalin following fermentation. Other extraction conditions that could warrant a complete solubilization of EA were evaluated. Using a 1:100 solid to solvent ratio and DMSO as the solvent, EA was obtained in 4% yields from S. cerevisiae fermented husks at a high purity degree. Hydrolytic treatment of S. cerevisiae fermented pomegranate husks afforded a material freed of the polysaccharides components that gave recovery yields of EA up to 12% w/w.


Assuntos
Ácido Elágico/química , Frutas/química , Resíduos Sólidos , Aspergillus niger/química , Aspergillus niger/metabolismo , Ácido Elágico/isolamento & purificação , Etanol/química , Fermentação , Hidrólise , Taninos Hidrolisáveis/química , Taninos Hidrolisáveis/isolamento & purificação , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo
15.
J Ind Microbiol Biotechnol ; 46(12): 1669-1683, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31531745

RESUMO

Due to the potential toxicity of mercury, there is an immediate need to understand its uptake, transport and flux within living cells. Conventional techniques used to analyze Hg2+ are invasive, involve high cost and are less sensitive. In the present study, a highly efficient genetically encoded mercury FRET sensor (MerFS) was developed to measure the cellular dynamics of Hg2+ at trace level in real time. To construct MerFS, the periplasmic mercury-binding protein MerP was sandwiched between enhanced cyan fluorescent protein (ECFP) and venus. MerFS is pH stable, offers a measurable fluorescent signal and binds to Hg2+ with high sensitivity and selectivity. Mutant MerFS-51 binds with an apparent affinity (Kd) of 5.09 × 10-7 M, thus providing a detection range for Hg2+ quantification between 0.210 µM and 1.196 µM. Furthermore, MerFS-51 was targeted to Escherichia coli (E. coli), yeast and human embryonic kidney (HEK)-293T cells that allowed dynamic measurement of intracellular Hg2+ concentration with a highly responsive saturation curve, proving its potential application in cellular systems.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Mercúrio/análise , Transporte Biológico , Sobrevivência Celular , Escherichia coli/química , Células HEK293 , Humanos , Espaço Intracelular/química , Saccharomyces cerevisiae/química
16.
J Med Food ; 22(10): 1009-1021, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31536448

RESUMO

Constipation is a common gastrointestinal disorder characterized by changes in intestinal habits. Increasing evidence indicates that long-term use of irritant laxatives causes serious side effects. Meanwhile, more than 50% of patients are dissatisfied with sense of use of non-prescriptional laxatives. ß-glucans are natural polysaccharides widely found in yeast, fungus, and plants, which have been reported to exhibit various pharmacological effects. The aim of this study was to characterize the effect of ß-glucans extracted from the bread yeast cell wall on loperamide-induced constipation mice. Forty mice were fed with loperamide (10 mg/kg) to make the constipation model and a diet supplemented with 2.5, 5, and 10 mg/kg ß-glucan. We assessed the defecation frequency, intestinal transit function of mice, as well as used high-throughput sequencing to analyze the intestinal microbiota composition and functional biological profiles data. Meanwhile, we detected expression of neurotransmitters including acetylcholinesterase, substance P, and serotonin (5-HT) and expression of tight junction protein (TJP) including zonula occludens-1 and mucin-2 in distal colon to characterize the possible molecular mechanisms. ß-glucans significantly enhanced intestinal motility and provided a possibility to regulate the expression of neurotransmitters and TJP in mice. The intestinal microecological portion of the treatment group partially recovered and was closer to the normal group. This study showed that ß-glucans can influence the intestinal microbiota and restore microecological balance to regulate the express of neurotransmitters and TJP to recover intestinal epithelial mechanical barrier. We suggested that ß-glucans could be used as an active nutritional supplement to protect the damaged intestinal barrier and help patients who have constipation complications and dysbiosis.


Assuntos
Constipação Intestinal/tratamento farmacológico , Microbioma Gastrointestinal , Loperamida/efeitos adversos , Saccharomyces cerevisiae/química , beta-Glucanas/farmacologia , Acetilcolinesterase/metabolismo , Animais , Constipação Intestinal/induzido quimicamente , Defecação/efeitos dos fármacos , Trânsito Gastrointestinal/efeitos dos fármacos , Masculino , Metagenoma , Camundongos , Camundongos Endogâmicos BALB C , Mucina-2/metabolismo , Serotonina/metabolismo , Substância P/metabolismo , Proteína da Zônula de Oclusão-1/metabolismo
17.
Int J Mol Sci ; 20(17)2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31480444

RESUMO

The mismatch repair (MMR) pathway maintains genome integrity by correcting errors such as mismatched base pairs formed during DNA replication. In MMR, Msh2-Msh6, a heterodimeric protein, targets single base mismatches and small insertion/deletion loops for repair. By incorporating the fluorescent nucleoside base analog 6-methylisoxanthopterin (6-MI) at or adjacent to a mismatch site to probe the structural and dynamic elements of the mismatch, we address how Msh2-Msh6 recognizes these mismatches for repair within the context of matched DNA. Fluorescence quantum yield and rotational correlation time measurements indicate that local base dynamics linearly correlate with Saccharomyces cerevisiae Msh2-Msh6 binding affinity where the protein exhibits a higher affinity (KD ≤ 25 nM) for mismatches that have a significant amount of dynamic motion. Energy transfer measurements measuring global DNA bending find that mismatches that are both well and poorly recognized by Msh2-Msh6 experience the same amount of protein-induced bending. Finally, base-specific dynamics coupled with protein-induced blue shifts in peak emission strongly support the crystallographic model of directional binding, in which Phe 432 of Msh6 intercalates 3' of the mismatch. These results imply an important role for local base dynamics in the initial recognition step of MMR.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteína 2 Homóloga a MutS/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Pareamento Incorreto de Bases , DNA Fúngico/genética , DNA Fúngico/metabolismo , Proteínas de Ligação a DNA/química , Modelos Moleculares , Proteína 2 Homóloga a MutS/química , Ligação Proteica , Conformação Proteica , Multimerização Proteica , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química
18.
Artigo em Inglês | MEDLINE | ID: mdl-31393235

RESUMO

Urea is a non-protein nitrogen compound, authorised in the EU as a nutritional source of nitrogen in animal feed intended for ruminants with a functional rumen. The Rapid Alert System for Food and Feed (RASFF) is the EU online platform through which food and feed safety risks are reported. During 2017, several rapid alerts were raised in the EU by individual member states regarding the presence of unlabelled urea in feed-grade yeast. The presence of urea in animal feed is analysed with a spectro-colorimetric method, which is the EU official control method. Other urea analytical methods include enzymatic and LC-MS methods, which are also investigated in this study. The main objectives of this study were to analyse yeast feed-grade and food-grade products with independent laboratories using the EU official control method, as well as enzymatic and LC-MS methods. Comparison of results from the spectro-colorimetric, enzymatic and LC-MS methods for reliability, consistency and accuracy determined the most reliable method for the quantification of urea in animal feed. Yeast food and feed samples were tested using four independent laboratories. Results demonstrated a lack of consistency both within the same laboratory and between separate laboratories for urea quantification using the EU official control method. Urea quantification results for the AOAC 941.04 enzymatic method were found to be much higher than anticipated. The LC-MS method yielded the most consistent and reliable results. In conclusion, urea quantification by LC-MS analysis has the potential to be a viable method for urea analysis of yeast samples.


Assuntos
Ração Animal/análise , Análise de Alimentos , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/isolamento & purificação , Ureia/análise , Animais , Cromatografia Líquida , Colorimetria , Espectrometria de Massas
19.
Environ Sci Pollut Res Int ; 26(28): 29366-29378, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31396876

RESUMO

The aim of this study was to improve the ethanol production from pomegranate peels (PPs). Therefore, the effect of enzymatic hydrolysis and different pretreatments on ethanol production by yeasts was examined. There were three different enzyme concentrations (3.6, 7.2, 14.4 FPU/g substrate) tested for enzymatic hydrolysis, and four different PP media, such as WSPP (whole slurry of PP), LFPP (liquid fraction of PP), WSFPP (washed solid fraction of PP) and N-WSFPP (non-washed solid fraction of PP), were prepared. Bioethanol production was monitored for 96 h. Maximum ethanol concentrations were obtained at WSPP medium as 12.69 g/L, 14.35 g/L and 4.23 g/L in Saccharomyces cerevisiae, Kluyveromyces marxianus and Pichia stipitis, respectively. On the other hand, the washing step of biomass increased the kinetic parameters dramatically and the highest theoretical ethanol yields and YP/S values were obtained from WSFPP medium in all tested yeasts. Theoretical ethanol yields were 97.8%, 98.7% and 35.5% for S. cerevisiae, K. marxianus and P. stipitis, respectively. Qp values were observed as 0.98 g/L h, 0.99 g/L h and 0.04 g/L h for the same yeasts. The highest YP/S values were detected as 0.50 g/g for S. cerevisiae, 0.50 g/g for K. marxianus and 0.30 g/g for P. stipitis in the washed pomegranate peel biomass.


Assuntos
Etanol/química , Lythraceae/química , Pichia/metabolismo , Saccharomyces cerevisiae/química , Biomassa , Etanol/metabolismo , Fermentação , Hidrólise/efeitos dos fármacos , Lythraceae/metabolismo , Pichia/química , /metabolismo
20.
Environ Sci Pollut Res Int ; 26(28): 29388-29396, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31399833

RESUMO

Crop straw is an abundant renewable resource whose usage is limited due to its high cellulose, hemicellulose, and lignin contents. Here, Trichoderma viride, Saccharomyces cerevisiae, and Musca domestica were used to transform crop straws, and we investigated their impact on housefly rearing performance and optimized their utilization. The weights of cellulose, hemicellulose, and lignin in fermented crop straw diets significantly decreased after bioconversion by M. domestica larvae. The highest bioconversion rate was recorded in corn straw diet (16.19%), followed by wheat straw diet (10.31%) and wheat bran diet (8.97%). Similarly, high larval weight (yield) and pupation rate and fecundity and fertility rate were recorded in fermented crop straw diets composed of corn straw and wheat bran in 1:1 proportions. These results indicated that fermenting crop straw with T. viride and S. cerevisiae represented an efficient strategy that enhanced crop straw bioconversion and improved the rearing capacity of the housefly larvae. The resulting larvae could further be used as proteinaceous feed in poultry and aquaculture industries. Graphical abstract.


Assuntos
Celulose/metabolismo , Lignina/metabolismo , Muscidae/química , Saccharomyces cerevisiae/metabolismo , Trichoderma/metabolismo , Triticum/microbiologia , Animais , Reatores Biológicos , Celulose/química , Fermentação , Moscas Domésticas , Larva/metabolismo , Lignina/química , Polissacarídeos , Saccharomyces cerevisiae/química , Trichoderma/química , Triticum/química , Triticum/metabolismo
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