RESUMO
Lipases are used in many food, energy, and pharmaceutical processes. Thus, new systems have been sought to synthesize alternative lipases with potential biotechnological applications. Kluyveromyces marxianus is a yeast with recognized lipase activity; at least ten putative lipases/esterases in its genome have been detected, and two of them possess a signal peptide for extracellular secretion. The study of extracellular lipases becomes more relevant since they usually have higher activity rates than intracellular lipases and simpler purification mechanisms. For these reasons, this study aimed to characterize the production and lipase activity of the putative extracellular lipases of the K. marxianus L-2029 strain, encoded in the genes LIP3 and YJR107W. Both genes were heterologously expressed in Saccharomyces cerevisiae BY4742 (yeast strain without extracellular lipase activity) using a pYES2.1/V5-His-TOPO® plasmid. Herein, we show evidence that the strain transformed with the LIP3 gene did not show lipase activity during flask galactose induction. On the other hand, the strain transformed with the YJR107W gene showed a specific activity of 0.397 U/mg, with an optimum temperature of 37 °C and pH 6. For maximum cell production, glucose and yeast extract concentrations were evaluated by a 22 factorial design, followed by the validation of the best concentrations predicted by a statistical model; a 22 factorial design was also carried out to evaluate the concentration of the inducer galactose on the transformed strains, and the intracellular and extracellular lipase specific activities were quantified. Finally, the biomass and lipase production were determined for each strain, which was grown in a stirred tank bioreactor with a working volume of 1.5 L. The specific activities of the transformed strains obtained in the bioreactor were 1.36 U/mg for the LIP3 transformant and 1.25 U/mg for the YJR107W transformant, respectively.
RESUMO
The objective of this study was to evaluate the ß-glucosidase activity in the non-conventional yeasts under cellulose, glucose and sucrose substrates. The participation of the enzyme ß-glucosidase and its contribution to the enzymatic degradation of tannins is known. Within the classification of tannins are ellagitannins, molecules of gallic acid and ellagic acid, which are considered as nutraceutical compounds due to the properties that they present and that they can be used in the design of food and new drugs, synthesis of materials with antimicrobial capacity. The extracellular ß-glucosidase activity was mainly presented in the Candida and Pichia strains, being the glucose and sucrose media the most capable for inducing the activity that showed maximum values with P. pastoris in glucose (0.1682±0.00 µmol/min mg protein), and C. utilis in cellulose (0.1129±0.1349 µmol/min mg of protein), and sucrose (0.0657±0.0214 µmol/min mg protein). Additionally, I. terricola and P. kluyvery stood out in a qualitative cellulose degradation approach measured by Congo red method (9.60±0.04 mm and 9.20±0.05 mm respectively). These indicate that P. pastoris and C. utilis have potential as ß-glucosidase producers, especially when growing under complex carbon sources for biomass conversion, new biofuels production and polyphenol degradation with more manageable bioreactor process.
Assuntos
Celulases , Taninos , Leveduras , Celulose/metabolismo , Glucose , Sacarose , beta-Glucosidase/química , beta-Glucosidase/metabolismoRESUMO
Pomegranate (Punica granatum) contains secondary metabolites with antioxidant and bactericide activity; however, the study of the peel in the endemic varieties of Mexico has not been deepened. The polyphenols extraction of peel pomegranate endemic to the state of Michoacan, Mexico could be used in the formlulation of healthy food due contains antioxidant compounds or could be used like drugs due contains antibactericide compunds.In this work 3 varieties of pomegranate were analyzed; Wonderful, Apaseo and Tecozautla harvested in 2017 and 2018, carrying out a physicochemical characterization to establish the ripening, application of an experimental design of response surface for drying the peel and extracting polyphenols using two solvents (acetone and ethanol) by the Soxhlet method. As a result, the pomegranates were in the correct ripening, in the drying an optimal point of operation was found without affecting the metabolites (36 h at 55 °C) and in the extraction, the bactericide and antioxidant activity was evaluated observing that in the ketone extracts the best results were obtained in the Apaseo variety being; ABTSâ¢+ technique of 150.78 ET mM/g, DPPH⢠109.8 ET mM/g and 11.82 EAG mg/g in dry extract. For the bactericide activity measured by inhibition halos in S. aureus and E. coli it was had; 20.03 mm and 14.05 mm respectively for the Apaseo variety, which is why it is convenient to extract polyphenols under this method in peel of Mexican pomegranate varieties.
Assuntos
Punica granatum , Antioxidantes/farmacologia , Escherichia coli , Staphylococcus aureus , Antibacterianos/farmacologia , Polifenóis/farmacologiaRESUMO
Abstract Ellagic acid (EA) is a phenolic biomolecule. For its biosynthesis, a source of ellagitannins is required, such as strawberries and yeasts, as precursors of the tannase and ß-glucosidase enzymes responsible for hydrolysis of ellagitannins. Two experimental mixture designs were applied., varying the yeast concentration and the number of ellagitannins in the culture medium, evaluating the enzymatic activity and ellagic acid biosynthesis. Aiming to find the optimal compositions of the non-conventional yeasts assessed in the research to biosynthesize ellagic acid feasibly and efficiently using a response surface performing the statistical analysis in the StatGraphics® program for obtaining a higher yield and optimizing the ellagic acid synthesis process, the results indicate that the strains Candida parapsilosis ITM LB33 and Debaryomyces hansenii ISA 1510 have a positive effect on the synthesis of ellagic acid, since as its concentration increases in the mixture the concentration of ellagic acid in the medium also increases; on the other hand, the addition of Candida utilis ITM LB02 causes a negative effect, resulting in the compositions of 0.516876, 0.483124 and 2.58687E-9 respectively, for a treatment under the same conditions, an optimal value of ellagic acid production would be obtained. With an approximate value of 7.33036 mg/mL
Assuntos
Leveduras/classificação , Reatores Biológicos/classificação , Ácido Elágico/síntese química , Otimização de Processos , Debaryomyces/classificação , Candida parapsilosis/classificaçãoRESUMO
C. vulgaris is a unicellular microalgae, whose growth depends on the conditions in which it is found, synthesizing primary and secondary metabolites in different proportions. Therefore, we analyzed and established conditions in which it was possible to increase the yields of metabolites obtained at the flask level, which could then be scaled to the photobioreactor level. As a methodology, a screening design was applied, which evaluated three factors: type of substrate (sodium acetate or glycerol); substrate concentration; and exposure-time to red light (photoperiod: 16:8 and 8:16 light/darkness). The response variables were: cell division; biomass; substrate consumption; and antioxidant activity in intracellular metabolites (ABTSâ¢+ and DPPHâ¢). As a result, the sodium acetate condition of 0.001 g/L, in a photoperiod of 16 h of light, presented a doubling time (Td = 4.84 h) and a higher rate of division (σ = 0.20 h-1), having a final biomass concentration of 2.075 g/L. In addition, a higher concentration of metabolites with antioxidant activity was found in the sodium acetate (0.629 Trolox equivalents mg/L ABTSâ¢+ and 0.630 Trolox equivalents mg/L DPPHâ¢). For the glycerol, after the same photoperiod (16 h of light and 8 h of darkness), the doubling time (Td) was 4.63 h, with a maximum division rate of σ = 0.18 h-1 and with a biomass concentration at the end of the kinetics of 1.4 g/L. Sodium acetate under long photoperiods, therefore, is ideal for the growth of C. vulgaris, which can then be scaled to the photobioreactor level.
Assuntos
Chlorella vulgaris , Microalgas , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Benzotiazóis , Biomassa , Glicerol/metabolismo , Cinética , Microalgas/metabolismo , Acetato de Sódio/metabolismo , Ácidos SulfônicosRESUMO
Quercetin is a flavonol ubiquitously present in fruits and vegetables that shows a potential therapeutic use in non-transmissible chronic diseases, such as cancer and diabetes. Although this phytochemical has shown promising health benefits, the molecular mechanism behind this compound is still unclear. Interestingly, quercetin displays toxic properties against phylogenetically distant organisms such as bacteria and eukaryotic cells, suggesting that its molecular target resides on a highly conserved pathway. The cytotoxicity of quercetin could be explained by energy depletion occasioned by mitochondrial respiration impairment and its concomitant pleiotropic effect. Thereby, the molecular basis of quercetin cytotoxicity could shed light on potential molecular mechanisms associated with its health benefits. Nonetheless, the evidence supporting this hypothesis is still lacking. Thus, this study aimed to evaluate whether quercetin supplementation affects mitochondrial respiration and whether this is related to quercetin cytotoxicity. Saccharomyces cerevisiae was used as a study model to assess the effect of quercetin on energetic metabolism. Herein, we provide evidence that quercetin supplementation: (1) decreased the exponential growth of S. cerevisiae in a glucose-dependent manner; (2) affected diauxic growth in a similar way to antimycin A (complex III inhibitor of electron transport chain); (3) suppressed the growth of S. cerevisiae cultures supplemented with non-fermentable carbon sources (glycerol and lactate); (4) promoted a glucose-dependent inhibition of the basal, maximal, and ATP-linked respiration; (5) diminished complex II and IV activities. Altogether, these data indicate that quercetin disturbs mitochondrial respiration between the ubiquinone pool and cytochrome c, and this phenotype is associated with its cytotoxic properties.
Assuntos
Quercetina , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Quercetina/farmacologia , Quercetina/metabolismo , Mitocôndrias/metabolismo , Glucose/metabolismo , RespiraçãoRESUMO
The Crabtree effect molecular regulation comprehension could help to improve ethanol production with biotechnological purposes and a better understanding of cancer etiology due to its similarity with the Warburg effect. Snf1p/Hxk2p/Mig1p pathway has been linked with the transcriptional regulation of the hexose transporters and phenotypes associated with the Crabtree effect. Nevertheless, direct evidence linking the genetic control of the hexose transporters with modulation of the Crabtree effect phenotypes by the Snf1p/Hxk2p/Mig1p pathway is still lacking. In this sense, we provide evidence that SNF1 and HXK2 genes deletion affects exponential growth, mitochondrial respiration, and transcript levels of hexose transporters in a glucose-dependent manner. The Vmax of the hexose transporters with the high transcript levels was correlated positively with the exponential growth and negatively with the mitochondrial respiration. HXT2 gene transcript levels were the most affected by the deletion of the SNF1/HXK2/MIG1 pathway. Deleting the orthologous genes SNF1 and HXK2 in Kluyveromyces marxianus (Crabtree negative yeast) has an opposite effect compared to Saccharomyces cerevisiae in growth and mitochondrial respiration. Overall, these results indicate that the SNF1/HXK2/MIG1 pathway regulates transcript levels of the hexose transporters, which shows an association with the exponential growth and mitochondrial respiration in a glucose-dependent manner.
Assuntos
Hexoquinase , Proteínas Serina-Treonina Quinases , Proteínas Repressoras , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Glucose/metabolismo , Hexoquinase/genética , Hexoquinase/metabolismo , Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Respiração , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
Los objetivos de la presente investigación fueron dos: a) analizar la relación entre los climas motivacionales generados por el entrenador y los iguales, y las características psicológicas en función del género y la edad de los jugadores y b) determinar las variables predictoras de los diferentes recursos psicológicos para el rendimiento deportivo de los jugadores de balonmano. Se administraron las escalas de Características psicológicas para el rendimiento Deportivo, Clima Motivacional Percibido en el Deporte y Clima Motivacional de los Iguales en el Deporte a 149 jugadores de balonmano (Medad = 15.11 años; Mexperiencia = 1.48 años; Mentrenamientos = 1.80 horas/semanales). Se realizó un análisis de correlaciones y predictivo, donde los resultados muestran que a medida que aumenta la percepción de un clima motivacional orientado a la tarea, aumenta el control del estrés y el número de horas de práctica del balonmano, y disminuye la evaluación sobre el rendimiento. Estos resultados sugieren que el entrenador, a través del diseño de entrenamientos orientados hacia la tarea, facilita que los deportistas dispongan de recursos psicológicos para sentirse eficaces y mantenerse en la actividad deportiva
The objectives of the present research were twofold: a) to analyse the relationship between the motivational climates generated by the coach and peers and the psychological characteristics as a function of gender and age of the players and b) to determine the predictor variables of the different psychological resources for the sport performance of handball players. The Psychological Characteristics for Sports Performance, Perceived Motivational Climate in Sport, and Peer Motivational Climate in Sport scales was administered to 149 handball players (Maturity = 15.11 years; Mexperience = 1.48 years; Training = 1.80 hours/week). A correlational and predictive analysis was conducted, where the results show that as the perception of a task-oriented motivational climate increases, stress management and the number of hours of handball practice increases, and performance appraisal decreases. These results suggest that the coach, through task-oriented training, facilitates the athletes to have psychological resources to feel effective and remain in the sports activity
Assuntos
Humanos , Masculino , Feminino , Adolescente , Esportes , Desempenho Atlético/psicologia , Motivação , Testes Psicológicos , Fatores Sexuais , Inquéritos e Questionários , Fatores Etários , Influência dos ParesRESUMO
Lipases are hydrolytic enzymes that break the ester bonds of triglycerides, generating free fatty acids and glycerol. Extracellular lipase activity has been reported for the nonconventional yeast Kluyveromyces marxianus, grown in olive oil as a substrate, and the presence of at least eight putative lipases has been detected in its genome. However, to date, there is no experimental evidence on the physiological role of the putative lipases nor their structural and catalytic properties. In this study, a bioinformatic analysis of the genes of the putative lipases from K. marxianus L-2029 was performed, particularly identifying and characterizing the extracellular expected enzymes, due to their biotechnological relevance. The amino acid sequence of 10 putative lipases, obtained by in silico translation, ranged between 389 and 773 amino acids. Two of the analysed putative proteins showed a signal peptide, 25 and 33 amino acids long for KmYJR107Wp and KmLIP3p, and a molecular weight of 44.53 and 58.23 kDa, respectively. The amino acid alignment of KmLIP3p and KmYJR107Wp with the crystallized lipases from a patatin and the YlLip2 lipase from Yarrowia lipolytica, respectively, revealed the presence of the hydrolase characteristic motifs. From the 3D models of putative extracellular K. marxianus L-2029 lipases, the conserved pentapeptide of each was determined, being GTSMG for KmLIP3p and GHSLG for KmYJR107Wp; besides, the genes of these two enzymes (LIP3 and YJR107W) are apparently regulated by oleate response elements. The phylogenetic analysis of all K. marxianus lipases revealed evolutionary affinities with lipases from abH15.03, abH23.01, and abH23.02 families.
Assuntos
Proteínas de Bactérias/química , Biologia Computacional , Kluyveromyces/enzimologia , Lipase/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Biocatálise , Hidrólise , Kluyveromyces/genética , Lipase/genéticaRESUMO
INTRODUCTION: Thromboelastometry evaluates viscoelastic changes in the coagulation process. It offers a graphic representation of the formation of the coagulum, its stability and the presence of lysis. OBJECTIVE: This first case of transfusion management guided by thromboelastography in Mexico and we conducted a review of the literature. METHOD: A metasearch search was performed (PubMed, Scielo, Medigraphic) with the words thromboelastometry, coagulopathy, transfusion medicine and the most influential works were included. CONCLUSIONS: The rotational thromboelastometry is a diagnostic tool that graphs the functionality of the clot, for a directed and individualized management of the coagulopathy associated with bleeding.
INTRODUCCIÓN: La tromboelastometría evalúa los cambios viscoelásticos en el proceso de coagulación. Ofrece una representación gráfica de la formación del coágulo, su estabilidad y la presencia de lisis. OBJETIVO: Se notifica el primer caso de manejo transfusional guiado por tromboelastografía en México con revisión de la bibliografía. MÉTODO: Se realizó una búsqueda en metabuscadores (PubMed, Scielo, Medigraphic) con las palabras tromboelastometría, coagulopatía y medicina transfusional y se incluyeron los trabajos más influyentes. CONCLUSIONES: La tromboelastometría rotacional es una herramienta diagnóstica que grafica la funcionalidad del coágulo para un manejo dirigido e individualizado de la coagulopatía relacionada con hemorragia.
Assuntos
Transfusão de Componentes Sanguíneos/métodos , Choque/terapia , Tromboelastografia/métodos , Tempo de Coagulação do Sangue Total/métodos , Adolescente , Afibrinogenemia/tratamento farmacológico , Afibrinogenemia/etiologia , Plaquetas/fisiologia , Traumatismos Craniocerebrais/complicações , Traumatismos Craniocerebrais/cirurgia , Soluções Cristaloides/administração & dosagem , Emergências , Transfusão de Eritrócitos/métodos , Evolução Fatal , Feminino , Fibrinogênio/uso terapêutico , Humanos , México , Plasma , Choque/etiologia , Ferimentos por Arma de Fogo/complicações , Ferimentos por Arma de Fogo/cirurgiaRESUMO
Resveratrol is a phytochemical that may promote health. However, it has also been reported to be a toxic compound. The molecular mechanism by which resveratrol acts remains unclear. The inhibition of the oxidative phosphorylation (OXPHOS) pathway appears to be the molecular mechanism of resveratrol. Taking this into account, we propose that the cytotoxic properties of resveratrol depend on the energy (e.g., carbohydrates, lipids, and proteins) availability in the cells. In this regard, in a condition with low energy accessibility, resveratrol could enhance ATP starvation to lethal levels. In contrast, when cells are supplemented with high quantities of energy and resveratrol, the inhibition of OXPHOS might produce a low-energy environment, mimicking the beneficial effects of caloric restriction. This review suggests that investigating a possible complex relationship between caloric intake and the differential effects of resveratrol on OXPHOS may be justified. PRACTICAL APPLICATIONS: A low-calorie diet accompanied by significant levels of resveratrol might modify cellular bioenergetics, which could impact cellular viability and enhance the anti-cancer properties of resveratrol.
Assuntos
Ingestão de Energia/fisiologia , Resveratrol/toxicidade , Trifosfato de Adenosina/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Homeostase/fisiologia , Humanos , Fosforilação Oxidativa/efeitos dos fármacosRESUMO
The switch between mitochondrial respiration and fermentation as the main ATP production pathway through an increase glycolytic flux is known as the Crabtree effect. The elucidation of the molecular mechanism of the Crabtree effect may have important applications in ethanol production and lay the groundwork for the Warburg effect, which is essential in the molecular etiology of cancer. A key piece in this mechanism could be Snf1p, which is a protein that participates in the nutritional response including glucose metabolism. Thus, this work aimed to recognize the role of the SNF1 gene on the glycolytic flux and mitochondrial respiration through the glucose concentration variation to gain insights about its relationship with the Crabtree effect. Herein, we found that SNF1 deletion in Saccharomyces cerevisiae cells grown at 1% glucose, decreased glycolytic flux, increased NAD(P)H concentration, enhanced HXK2 gene transcription, and decreased mitochondrial respiration. Meanwhile, the same deletion increased the mitochondrial respiration of cells grown at 10% glucose. Altogether, these findings indicate that SNF1 is important to respond to glucose concentration variation and is involved in the switch between mitochondrial respiration and fermentation.
Assuntos
Glucose/metabolismo , Mitocôndrias/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Saccharomyces cerevisiae/metabolismo , Fermentação , Glucose/análise , Glicólise , Hexoquinase/genética , NAD/metabolismo , Proteínas Serina-Treonina Quinases/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Deleção de Sequência , Transcrição GênicaRESUMO
OBJECTIVE: Angiotensin II (Ang-II) antagonism alleviates hypertensive kidney damage by improving mitochondrial function and decreasing oxidative stress. This condition also is associated with altered renal vascular tone due to enhanced constriction by Ang-II. Thus, approaches ameliorating these events are desirable to alleviate kidney damage. Avocado oil, a source of antioxidants and oleic acid, is known to improve mitochondrial function, while oleic acid has antihypertensive effects. Therefore, the aim of this study was to test whether avocado oil counteracts, to a similar degree as the Ang-II blocker losartan, the deleterious effects of hypertension on blood pressure, renal vascular performance, kidney mitochondrial function, and oxidative stress. METHODS: Hypertensive rats induced with Nω-nitro-l-arginine methyl ester (L-NAME) were supplemented during 45 d with avocado oil or losartan. Vascular responses were analyzed in perfused kidney. Membrane potential, reactive oxygen species levels, and glutathione were analyzed in isolated kidney mitochondria. RESULTS: In hypertensive rats, avocado oil decreased 21.2% and 15.5% diastolic and systolic blood pressures, respectively, and alleviated impaired renal vasodilation. Hypertension decreased membrane potential by 83.7% and augmented reactive oxygen species levels by 51% in mitochondria fueled with a complex I substrate, whereas it augmented the levels of oxidized glutathione in 48%. These alterations were normalized by avocado oil at a comparable degree to losartan. CONCLUSIONS: Because avocado oil mimicked the effects of losartan, we propose that the effects of avocado oil might be mediated by decreasing the actions of Ang-II on mitochondria. These results suggest that avocado oil intake might be a nutritional approach to attenuate the deleterious effects of hypertension on kidney.
Assuntos
Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/terapia , Losartan/farmacologia , Persea , Óleos de Plantas/farmacologia , Antagonistas de Receptores de Angiotensina/farmacologia , Animais , Modelos Animais de Doenças , Glutationa/metabolismo , Hipertensão/fisiopatologia , Rim/irrigação sanguínea , Rim/metabolismo , Masculino , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Vasodilatação/efeitos dos fármacosRESUMO
Nutritional homeostasis is fundamental for alcoholic fermentation in Saccharomyces cerevisiae. Carbon and nitrogen have been related to this metabolic process; nevertheless, little is known about their interactions with the media and the energetic metabolism. Rim15p kinase is a point of convergence among different nutrient-activated signaling pathways; this makes it a target to investigate the relationship between nutritional status and energetic metabolism. To improve the current knowledge of nutrient interactions and their association with RIM15, we validated the doubling time as an indicator of growth phenotype, confirming that this kinetic parameter can be related to the cellular bioenergetic status. This endorses the usefulness of a threshold in doubling time values as an indicator of fermentative (≤ 6.5 h) and respiratory growth (≥ 13.2 h). Using the doubling time as response variable, we find that (i) two second-order interactions between type and concentration of carbon and nitrogen sources significantly affected the growth phenotype of S. cerevisiae; (ii) these metabolic interactions changed when RIM15 was deleted, suggesting a dependence on this gene; (iii) high concentration of ammonium (5% w/v) is toxic for S. cerevisiae cells; (iv) proline prompted fermentative growth phenotype regardless presence or absence of RIM15; (v) RIM15 deletion reverted ammonium toxicity when cells were grown in glucose (10% w/v); and (vi) RIM15 deletion improves fermentative metabolism probably by a partial inhibition of the respiration capacity. This study reveals the existence of synergic and diverse roles of carbon and nitrogen sources that are affected by RIM15, influencing the fermentative and respiratory growth of S. cerevisiae.
Assuntos
Carbono/metabolismo , Nitrogênio/metabolismo , Proteínas Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Fermentação , Glucose/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimentoRESUMO
A broad range of health benefits have been attributed to resveratrol (RSV) supplementation in mammalian systems, including the increases in longevity. Nonetheless, despite the growing number of studies performed with RSV, the molecular mechanism by which it acts still remains unknown. Recently, it has been proposed that inhibition of the oxidative phosphorylation activity is the principal mechanism of RSV action. This mechanism suggests that RSV might induce mitochondrial dysfunction resulting in oxidative damage to cells with a concomitant decrease of cell viability and cellular life span. To prove this hypothesis, the chronological life span (CLS) of Saccharomyces cerevisiae was studied as it is accepted as an important model of oxidative damage and aging. In addition, oxygen consumption, mitochondrial membrane potential, and hydrogen peroxide (H2O2) release were measured in order to determine the extent of mitochondrial dysfunction. The results demonstrated that the supplementation of S. cerevisiae cultures with 100 µM RSV decreased CLS in a glucose-dependent manner. At high-level glucose, RSV supplementation increased oxygen consumption during the exponential phase yeast cultures, but inhibited it in chronologically aged yeast cultures. However, at low-level glucose, oxygen consumption was inhibited in yeast cultures in the exponential phase as well as in chronologically aged cultures. Furthermore, RSV supplementation promoted the polarization of the mitochondrial membrane in both cultures. Finally, RSV decreased the release of H2O2 with high-level glucose and increased it at low-level glucose. Altogether, this data supports the hypothesis that RSV supplementation decreases CLS as a result of mitochondrial dysfunction and this phenotype occurs in a glucose-dependent manner.
Assuntos
Longevidade/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Saccharomyces cerevisiae/citologia , Estilbenos/farmacologia , Antioxidantes/farmacologia , Glucose/farmacologia , Peróxido de Hidrogênio/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio , Resveratrol , Saccharomyces cerevisiae/efeitos dos fármacosRESUMO
In this study, total phenolics, total flavonoids, hesperidin and ascorbic acid contents in bagasse, juice and seed of mexican sweet lime (Citrus limetta) and mandarine (Citrus reticulata) were determined at two commercial maturity stages (maturation index), as well as their bactericidal effect on Escherichia coli and Staphylococcus aureus. The results showed that bagasses had the highest total phenolics, total flavonoids, and hesperidin content for both, C. limetta, and C. reticulata; highest ascorbic acid contents were found in C. limetta juice (3.36 ± 0.25 mg g-1 DW) and C. reticulata bagasse (3.83 ± 0.37 mg g-1 DW). All tested extracts showed bacterial growth inhibition at 50 and 800 µg mL-1. Bagasse extracts of both fruits showed the highest inhibitions (>90%) on tested bacteria. Total phenolics, total flavonoids, and hesperidin contents, as well as bactericidal effect increased with maturity. Results indicated that both Mexican citric fruits (C. limetta and C. reticulata) were good sources of antioxidant and bactericidal agents.
RESUMO
En la industria alimenticia, los agentes microbicidas son usados para preservar la calidad y seguridad de los alimentos procesados. Los flavonoides encontrados en extractos cítricos han mostrado capacidad de inhibición del crecimiento celular de un gran grupo de microorganismos infecciosos, por lo tanto, éstos compuestos pueden ser útiles como agentes antivirales, antifúngicos y antibacteriales. Los flavonoides que se pueden encontrar principalmente en varias de las especies cítricas son hesperetina, hesperidina, luteolina, naringenina, naringina, narirutina, neohesperidina, nobiletina y tangeretina. A continuación se resumen los procesos utilizados recientemente para extraer, purificar y analizar los flavonoides principales en frutas cítricas. Ya optimizado el medio de cultivo se procedió a realizar una cinética confirmatoria con base a las condiciones encontradas pero evaluando el crecimiento celular por conteo en cámara de Neubauer y la producción de etanol mediante método enzimático (Procedimiento de ensayo K-ETOH, Megazyme) para confirmar los valores.
In the food industry, antimicrobial agents are used for preserving the quality and safety of processed food. Flavonoids found in citrus extracts inhibit cell growth of a large group of infectious microorganisms, therefore, these compounds may be useful as antiviral, antifungal and antibacterial agents. Hesperetin, hesperidin, luteolin, naringenin, naringin, narirutin, neohesperidin, nobiletin and tangeretin are some of the main flavonoids found in various citrus fruits. The processes used in recent years to extract, purify and analyze typical flavonoids from citrus species are reviewed.
RESUMO
En el presente trabajo, se efectuó una compilación de investigaciones realizadas sobre las diferentes etapas del proceso productivo del mezcal a partir de agave en algunas regiones productoras de México; con el propósito de explicar las problemáticas que enfrenta la cadena productiva agave-mezcal y las estrategias científicas que se han desarrollado para solucionarlas. Con ello se pretende lograr su resistencia y persistencia productiva en el mercado, elaborando un producto que cumpla con las características químicas establecidas por las normas oficiales mexicanas de producción y certificación de calidad, además de ofrecer posibles medidas de control en los procesos para estandarizar el producto y finalmente lograr etapas más eficientes en el proceso de producción.
In this paper, a compilation of investigations of the different stages in the production process of mezcal from agave in some producers regions of Mexico is carried out; to explain some of the problems faced by the productive chain agave-mezcal and scientific strategies that are being developed in the country to solve them. This is intended to achieve its resistance and productive persistence in the market, producing a product that meets the chemical characteristics established by the Mexican official standards of production and quality certification, in addition to establishing more measures of control processes to standardize the product and finally to achieve more efficient steps in the production process.
RESUMO
Las infecciones nosocomiales constituyen un importante problema de salud relacionado con la calidad de la atención y la eficacia del trabajo. El objetivo fue caracterizar las infecciones nosocomiales en el Hospital Pediátrico Provincial Docente Pepe Portilla durante el período 2010-2011. Se realizó una investigación observacional, descriptiva, transversal y aplicada. El universo estuvo conformado por los 22652 egresados y la muestra por los 516 casos. Para la obtención de la información se revisaron los registros del departamento de estadística y las historias clínicas, utilizándose para su análisis las frecuencias absolutas, relativas porcentuales y la prueba de X2 al 95 por ciento de certeza. El sistema respiratorio es el sitio de mayor localización, donde predominaron los hemocultivos negativos. Los gérmenes más aislados fueron: el Staphylococcus epidermidis, la Pseudomonas sp y el Acinetobacter, entre otros. Las infecciones nosocomiales en pediatría constituyen una problema de salud que requiere el fortalecimiento de las actividades de prevención y control, con especial énfasis en su vigilancia sistemática (AU)
Nosocomial infections constitute an important problem related to the quality and efficiency of the health services. The objective was to characterize nosocomial infections at Pepe Portilla Provincial Children Hospital during 2010-2011. An observational, descriptive, cross-sectional and applied research was conducted, which target group was comprised of 22652 patients discharged from the hospital and the sample included 516 patients. To collect the information, the records of the statistics department and the clinical histories were reviewed; where absolute frequencies and relative percentages plus chi square test up to 95 per cent of certainty were used to complete its analysis. Respiratory tract was the most affected site, where negative hemocultures prevailed. Staphylococcus epidermidis, Pseudomonas sp and Acinetobacter germs were the most isolated, among others. Nosocomial infections constitute a health problem in paediatrics, which requires the strengthening of prevention and control activities, emphasizing on its systemic surveillance (AU)
Assuntos
Humanos , Infecção Hospitalar , Serviços de SaúdeRESUMO
Introducción: las infecciones nosocomiales constituyen un importante problema de salud relacionado con la calidad de la atención y la eficacia del trabajo. Objetivo: caracterizar las infecciones nosocomiales en el Hospital Pediátrico Provincial Docente "Pepe Portilla" durante el período 2010-2011. Material y método: se realizó una investigación observacional, descriptiva, transversal y aplicada. El universo estuvo conformado por los 22652 egresados y la muestra por los 516 casos. Para la obtención de la información se revisaron los registros del departamento de estadística y las historias clínicas, utilizándose para su análisis las frecuencias absolutas, relativas porcentuales y la prueba de X² al 95 % de certeza. Resultados: el sistema respiratorio es el sitio de mayor localización, donde predominaron los hemocultivos negativos. Los gérmenes más aislados fueron: el Staphylococcus epidermidis, la Pseudomonas sp y el Acinetobacter, entre otros. Conclusiones: las infecciones nosocomiales en pediatría constituyen una problema de salud que requiere el fortalecimiento de las actividades de prevención y control, con especial énfasis en su vigilancia sistemática.
Introduction: nosocomial infections constitute an important problem related to the quality and efficiency of the health services. Objective: to characterize nosocomial infections at Pepe Portilla Provincial Children Hospital during 2010-2011. Material and method: an observational, descriptive, cross-sectional and applied research was conducted, which target group was comprised of 22652 patients discharged from the hospital and the sample included 516 patients. To collect the information, the records of the statistics department and the clinical histories were reviewed; where absolute frequencies and relative percentages plus chi square test up to 95% of certainty were used to complete its analysis. Results: respiratory tract was the most affected site, where negative hemocultures prevailed. Staphylococcus epidermidis, Pseudomonas sp and Acinetobacter germs were the most isolated, among others. Conclusions: nosocomial infections constitute a health problem in paediatrics, which requires the strengthening of prevention and control activities, emphasizing on its systemic surveillance.