Producción de enzimas ligninolíticas a partir de biomasa de Panicum maximum por Pleurotus ostreatus

El uso de la biomasa como principal materia prima para el desarrollo de productos con alto impacto en la mercado, tales como enzimas lacasas y peroxidasas con aplicaciones en biorremediación , la industria del papel, textil, alimentos y farmacéutica; presenta un creciente interés. El objetivo de esta investigación fue estudiar la obtención de un extracto enzimático ligninolítico a partir de biomasa lignocelulósica de Panicum maximum por Pleurotus ostreatus mediante una fermentación líquida sumergida. La producción enzimática fue evaluada bajo tres diferentes fuentes de nitrógeno: Carbonato de amonio (NH4)2CO3, Sulfato de Amonio (NH4)2SO4 y Peptona a valores de pH inicial de 4.5, 6.0 y 7.5 y relaciones carbono nitrógeno (C/N) (10, 20 y 30). Los mayores niveles de actividad enzimática para lacasas (4450.70 U/L) y manganeso peroxidasas (528.20 U/L) fueron obtenidos con peptona bajo las siguientes condiciones: pH: 7.5, una relación de C/N= 10, a los de nueve días de incubación a 28ºC a 150 rpm. Adicionalmente se evaluaron diferentes concentraciones de inóculo obteniendo los niveles más altos de actividad específica (24054.88 U/L. g de biomasa) a los ocho días de incubación. Como última fase experimental se evaluaron el efecto de la aireación y agitación en un reactor agitado con 1.7 L de volumen de reacción, los títulos de actividad lacasa más altos fueron 2418.85 U/L con una agitación igual a 200 rpm y aireación de 2 vvm, al octavo día de fermentación a 28° C.Abstract. The use of biomass as main feedstock for the development of products with high impact on market, such as laccases and peroxidases enzymes for different industrial applications, paper, textile, food and pharmaceutical; presents a growing interest. The objective of this investigation was to study obtaining a ligninolytic enzyme extract from lignocellulosic biomass of Panicum maximum by submerged liquid fermentation with Pleurotus ostreatus. Enzyme production was carried out with three different nitrogen sources: Ammonium carbonate (NH4) 2CO3, Ammonium Sulfate (NH4) 2SO4 and Peptone at pH 4.5, 6.0 and 7.5 and three different carbon to nitrogen ratio (C / N) (10, 20 and 30). The highest activities to laccases (4450.70 U / L) and peroxidases manganese (528.20 U / L) were obtained with peptone at the following conditions: pH: 7.5, and C / N = 10 after nine days incubation at 28 ° C at 150 rpm. Additionally different inoculum concentrations were evaluated, the highest levels of laccases specific activity (24054.88 U / L. G biomass) at eight days of incubation. Last experimental phase was to study the effect of the aeration and agitation in a stirred reactor with 1.7 L of reaction volume. Higher levels of laccase activity (2418.85 U / L) were obtained at 200 rpm and 2 vvm, after eighth day fermentation at 28 ° C.Maestrí

Development of a Bioreactor-Based Model for low-density polyethylene (LDPE) Biodegradation by Aspergillus brasiliensis

Low-density polyethylene (LDPE) is a widely used polymer due to its chemical resistance, highflexibility, and mechanical properties. However, its low degradation rate, coupled with its low lifespanand widespread accumulation, poses significant environmental and public health concerns. This studypresents a biodegradation model for LDPE using a suspension bioreactor, which could serve as abiological treatment alternative before polymer disposal. In our model, an initial culture ofAspergillusbrasiliensismetabolized the carbon within the polymer structure and used it as an energy source,leading to LPDE biodegradation and mineralization. The procedure took place in a laboratory-scalebioreactor prototype under aerobic conditions and submerged liquid fermentation. After one month ofculture, a biodegradation percentage of1:89 ̇0:56% was reached. The treated materials were analyzedby scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). We foundevidence of biodegradation, colonization of the material, and biofilm formation. This research providespreliminary data on the biodegradation of LDPE under submerged liquid fermentation, marking aninitial phase in the development of a prototype for polymer biodegradation

Neurological manifestations of COVID-19 in adults and children

Different neurological manifestations of coronavirus disease 2019 (COVID-19) in adults and children and their impact have not been well characterized. We aimed to determine the prevalence of neurological manifestations and in-hospital complications among hospitalized COVID-19 patients and ascertain differences between adults and children. We conducted a prospective multicentre observational study using the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) cohort across 1507 sites worldwide from 30 January 2020 to 25 May 2021. Analyses of neurological manifestations and neurological complications considered unadjusted prevalence estimates for predefined patient subgroups, and adjusted estimates as a function of patient age and time of hospitalization using generalized linear models. Overall, 161 239 patients (158 267 adults; 2972 children) hospitalized with COVID-19 and assessed for neurological manifestations and complications were included. In adults and children, the most frequent neurological manifestations at admission were fatigue (adults: 37.4%; children: 20.4%), altered consciousness (20.9%; 6.8%), myalgia (16.9%; 7.6%), dysgeusia (7.4%; 1.9%), anosmia (6.0%; 2.2%) and seizure (1.1%; 5.2%). In adults, the most frequent in-hospital neurological complications were stroke (1.5%), seizure (1%) and CNS infection (0.2%). Each occurred more frequently in intensive care unit (ICU) than in non-ICU patients. In children, seizure was the only neurological complication to occur more frequently in ICU versus non-ICU (7.1% versus 2.3%, P < 0.001). Stroke prevalence increased with increasing age, while CNS infection and seizure steadily decreased with age. There was a dramatic decrease in stroke over time during the pandemic. Hypertension, chronic neurological disease and the use of extracorporeal membrane oxygenation were associated with increased risk of stroke. Altered consciousness was associated with CNS infection, seizure and stroke. All in-hospital neurological complications were associated with increased odds of death. The likelihood of death rose with increasing age, especially after 25 years of age. In conclusion, adults and children have different neurological manifestations and in-hospital complications associated with COVID-19. Stroke risk increased with increasing age, while CNS infection and seizure risk decreased with age

Efecto de la fuente de nitrógeno en la producción de la enzima manganeso peroxidasa producida por Pleurotus ostreatus y determinación de sus constantes cinéticas

The use of lignocellulosic residues for the production of molecules of interest, such as sugars and biofuels, also includes the synthesis of enzymatic complexes composed by oxidases capable of degrading aromatic and phenolic structures of a pollution nature in certain cases. This study evaluated the production of manganese peroxidase (MnP) in a liquid fermentation submerged by Pleurotus ostreatus using as substrate a forage grass. The highest levels of enzymatic activity (528.54 U/L) were obtained after twelve days of incubation and having as a nitrogen source peptone, at a carbon/nitrogen ratio equal to 10. In the cases in which the fermentation was supplemented with inorganic nitrogen sources, the enzymatic activity was lower.La utilización de residuos lignocelulósicos para la producción de moléculas de interés, como azúcares o biocombustibles, también incluye la síntesis de complejos enzimáticos compuestos por oxidasas capaces de degradar, en ciertos casos, estructuras aromáticas y fenólicas de carácter contaminante. Este estudio evaluó la producción de manganeso peroxidasa (MnP) en una fermentación líquida sumergida por Pleurotus ostreatus, utilizando como sustrato la gramínea forrajera Panicum maximum. Los mayores niveles de actividad enzimática (528.54 U/L) fueron obtenidos a los doce días de incubación, empleando peptona como fuente de nitrógeno a una relación carbono/nitrógeno igual a diez. En los casos en los que la fermentación fue suplementada con fuentes de nitrógeno inorgánicas, la actividad enzimática fue más baj

Producción de un material biocompuesto a base de micelio por medio de fermentación sólida usando Pleurotus ostreatus

Expanded polystyrene (EPS) is a material used as packaging and the amount of EPS waste accumulated in landfills has driven progress in the production of biocomposite materials such as those produced from the mycelium generated by white rot fungi. The main objective of this study was the production of a biocomposite material obtained from the mycelium of Pleurotus ostreatus strain using malt bran and wheat bran as a substrate to be use as packaging material. We propose three mixtures: mixture A (50 % malt and 50 % wheat); mixture B (30 % malt and 70 % wheat) and mixture C (100 % wheat) using solid fermentations. Properties like moisture content, compressive strength, density, water absorption, electrical conductivity and pH were measured for each mixture. The best results were obtained in the mixture A with average compressive stress values ​​of 110,04 kPa for 10 % deformation, maximum water absorption of 172,01 % (36 hours), pH of 5,88, electrical conductivity of 1860 µS/cm and density of 233,17 kg/m3. When comparing the properties with EPS, it was found that the compressive stress is similar, however, properties such as density and water absorption present remarkably high values ​​for the biocomposite to be used in packaging.  El poliestireno expandido (EPS) es un material generalmente utilizado como embalaje y la cantidad de desechos de EPS acumulados en los vertederos ha impulsado el avance en la producción de materiales biocompuestos como los producidos a partir de micelios fúngicos. Este estudio tuvo como objetivo principal la producción de un material biocompuesto obtenido a partir del micelio de la cepa Pleurotus ostreatus usando afrecho de malta y salvado de trigo como sustrato con miras a ser usado como material para empaques y embalajes. Se realizaron tres mezclas diferentes, mezcla A (50 % afrecho y 50 % salvado); mezcla B (30 % afrecho y 70 % salvado) y mezcla C (0 % afrecho y 100 % salvado) para la realización de fermentaciones sólidas. Para la caracterización se midió el contenido de humedad, resistencia a la compresión, densidad, absorción de agua, conductividad eléctrica y pH. La mezcla que obtuvo mejor colonización y propiedades fue la mezcla A con valores de esfuerzo de compresión promedio de 110,04 kPa para un 10 % de deformación, absorción de agua máxima de 172,01 % (36 horas), pH de 5,88, conductividad eléctrica de 1860 µS/cm y una densidad de 233,17 kg/m3. Al comparar las propiedades con el EPS se encuentra que el esfuerzo a la compresión es similar, sin embargo, propiedades como la densidad y la absorción del agua presenta valores muy altos para que el biocompuesto pueda usarse en embalaje.

Relación entre trastornos alimentarios y familia e ideación suicida en adolescentes escolarizadas de Bogotá

Objective To show relationship among risk for eating disorders, suicidal ideation and family among female adolescents. Methods Descriptive cross-sectional study. Over 12 years, questionnaires were applied to 14,193 female adolescents enrolled in public schools in Suba locality in Bogotá, they were selected voluntarily. As explanatory variables, gender, age, stratum, functionality (using the family Apgar) and family structure (members with whom they live), suicidal ideation, mood, relationship with peers and self-esteem were investigated. The ORs were obtained. The Scoff questionnaire was used as a dependent variable. Results The mean age of the population was 13.9 years old. A prevalence of risk for eating disorders of 28.4% and of family dysfunction of 33% were found, severe family dysfunction increased the prevalence of eating disorders (OR 2,6, CI 95% 2.2-3.0) suicidal ideation (OR 3.5, CI 95% 3.0-4.0). Conclusions This research confirms the importance of the family in relation to the risk for eating disorders, as well as the relationship among suicidal ideation and distortio of body image. According to the findings, it is proposed to implement workshops that reduce the risk factors that cause disorders and strengthen the protective factors.Objetivo Estimar la relación entre el riesgo de trastornos alimentarios, la familia y la ideación suicida en una población adolescente femenina. Métodos Estudio descriptivo, transversal. A lo largo de 12 años se aplicaron cuestionarios a 14 193 adolescentes femeninas escolarizadas de los colegios públicos de la localidad de Suba en Bogotá, seleccionadas voluntariamente. Como variables explicativas se indagaron el género, la edad, el estrato, la funcionalidad (usando el Apgar familiar), la estructura familiar (miembros con los que se convive), la ideación suicida, el estado de ánimo, la relación con los pares y la autoestima. Como variable dependiente se realizó el cuestionario Scoff. Se obtuvieron los OR de esta relación. Resultados La edad media de la población fue de 13,9 años. Se encontró una prevalencia de riesgo de trastornos de la conducta alimentaria de 28,4% y de disfunción familiar de 33%. La disfunción familiar severa aumentó la prevalencia de trastornos de la conducta alimentaria (OR 2,6, IC 95% 2,2-3,0) y de ideación suicida (OR 3,5, IC 95% 3,0-4,0). Conclusiones Esta investigación confirma la importancia de la funcionalidad familiar en relación con el riesgo de trastornos de la conducta alimentaria, la ideación suicida y la distorsión de la imagen corporal. Con base en los hallazgos se propone implementar talleres que disminuyan los factores de riesgo causantes de los trastornos alimentarios y afiancen los factores protectores