Comparative analysis of ß-glucosidase activity in non-conventional yeasts.

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.

Obtaining polyphenolic extracts from pomegranate peel (Punica granatum) to evaluate the bactericide and antioxidant activity.

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; ABTS•+ 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.

Effects of home confinement on physical activity, nutrition, and sleep quality during the COVID-19 outbreak in amateur and elite athletes.

Introduction: Despite the progress in the management of the pandemic caused by COVID-19, it is necessary to continue exploring and explaining how this situation affected the athlete population around the world to improve their circumstances and reduce the negative impact of changes in their lifestyle conditions that were necessitated due to the pandemic. The aim of this study was to analyze the moderating influence of physical activity (PA) and dietary habits on the impact of the COVID-19 pandemic experience on sleep quality in elite and amateur athletes. Materials and methods: A total of 1,420 elite (40.1%) and amateur (59.9%) athletes (41% women; 59% men) from 14 different countries participated in a cross-sectional design study. Data were collected using a battery of questionnaires that identified sociodemographic data, sleep quality index, PA levels, dietary habits, and the athletes' perception of their experience during the COVID-19 pandemic. Means and standard deviations were calculated for each variable. The analysis of variances and the correlation between variables were carried out with non-parametric statistics. A simple moderation effect was calculated to analyze the interaction between PA or dietary habits on the perception of the COVID-19 experience effect on sleep quality in elite and amateur athletes. Results: The PA level of elite athletes was higher than amateur athletes during COVID-19 (p < 0.001). However, the PA level of both categories of athletes was lower during COVID-19 than pre-COVID-19 (p < 0.01). In addition, amateurs had a higher diet quality than elite athletes during the pandemic (p = 0.014). The perception of the COVID-19 experience as controllable was significantly higher (p = 0.020) among elite athletes. In addition, two moderating effects had significant interactions. For amateur athletes, the PA level moderated the effect of controllable COVID-19 experience on sleep quality [F (3,777) = 3.05; p = 0.028], while for elite athletes, the same effect was moderated by dietary habits [F (3,506) = 4.47, p = 0.004]. Conclusion: Elite athletes had different lifestyle behaviors compared to amateurs during the COVID-19 lockdown. Furthermore, the relevance of maintaining high levels of PA for amateurs and good quality dietary habits by elite athletes was noted by the moderating effect that both variables had on the influence of the controllable experience during the COVID-19 pandemic on sleep quality.

Optimization of the ellagic acid synthesis process at the bioreactor level using non-conventional yeasts

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

Cytotoxicity of quercetin is related to mitochondrial respiration impairment in Saccharomyces cerevisiae.

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.

Snf1p/Hxk2p/Mig1p pathway regulates hexose transporters transcript levels, affecting the exponential growth and mitochondrial respiration of Saccharomyces cerevisiae.

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.

¿Qué me ocurre cuando me influyen los demás? impacto en las características psicológicas de jóvenes jugadores de balonmano / What happens to me when I am influenced by others? impact on the psychological characteristics of handball players

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

Resveratrol cytotoxicity is energy-dependent.

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.

SNF1 controls the glycolytic flux and mitochondrial respiration.

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.

Comparative effects of avocado oil and losartan on blood pressure, renal vascular function, and mitochondrial oxidative stress in hypertensive rats.

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.

Glutathione levels influence chronological life span of Saccharomyces cerevisiae in a glucose-dependent manner.

Diet plays a key role in determining the longevity of the organisms since it has been demonstrated that glucose restriction increases life span whereas a high-glucose diet decreases it. However, the molecular basis of how diet leads to the aging process is currently unknown. We propose that the quantity of glucose that fuels respiration influences reactive oxygen species generation and glutathione levels, and both chemical species impact in the aging process. Herein, we provide evidence that mutation of the gene GSH1 in Saccharomyces cerevisiae diminishes glutathione levels. Moreover, glutathione levels were higher with 0.5% than in 10% glucose in the gsh1Δ and wild-type strains. Interestingly, the chronological life span was lowered in the gsh1Δ strain cultured with 10% glucose but not under dietary restriction. The gsh1Δ strain also showed inhibition of the mitochondrial respiration in 0.5 and 10% glucose but only increased the H2 O2 levels under dietary restriction. These results correlate well with the GSH/GSSG ratio, which showed a decrease in gsh1Δ strain cultured with 0.5% glucose. Together, these data indicate that glutathione exhaustion impact negatively both the electron transport chain function and the chronological life span of yeast, the latter occurring when a low threshold level of this antioxidant is reached, independently of the H2 O2 levels.

Polyphenolic content and bactericidal effect of Mexican Citrus limetta and Citrus reticulata.

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.

Procedimientos actuales para la extracción y purificación de flavonoides cítricos / Current procedures for extraction and purification of citrus flavonoides

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.

Revisión del agave y el mezcal / Review of agave and mezcal

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.

Caracterización de las infecciones nosocomiales / Characterization of nosocomial infections

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.

Prevalencia de anticuerpos contra Trypanosoma cruzi en donadores de sangre del IMSS, Orizaba, Veracruz, México / Prevalence of antibodies against Trypanossoma cruzi in blood bank donors from the IMSS General Hospital in Onizaba, Veracruz, Mexico

OBJETIVO: Determinar la prevalencia de anticuerpos contra Trypanosoma cruzi en donadores del Hospital General Regional del Instituto Mexicano del Seguro Social (IMSS) en la ciudad de Orizaba, Veracruz. MATERIAL Y MÉTODOS: Se examinaron muestras de donadores del banco de sangre del Hospital General Regional (HGRO) del IMSS para la búsqueda de antiT. cruzi por ELISA, Western blot e IFI, utilizando una proteína recombinante (MBP::Hsp70) y un extracto crudo de epimastigotes. Las muestras fueron obtenidas entre los meses de octubre de 2001 a enero de 2002. RESULTADOS: Los 420 donadores de sangre analizados fueron seronegativos para HBV, HCV, BrA, VDRL y HIV. Despu‚s del tamizaje de los 420 donadores, se identificaron dos individuos seropositivos por las pruebas de ELISA, Western blot e IFI, con una seroprevalencia de 0.48 por ciento. CONCLUSIONES: En este estudio se muestran evidencias de seropositividad para T. cruzi en donadores de sangre del HGRO, lo que sugiere la existencia de riesgo de contaminaci¢n por transfusión sanguínea. Por tal motivo, es necesario aplicar programas para el tamizaje serológico a través de técnicas inmunológicas con alta sensibilidad y especificidad.