Utilización de dos soportes para la inmovilización de la papaína

Papain was immobilized on activated carbon (AC) and on alumina (AL), with the aim of preparing low cost dietarysupplements, using whey as hydrolysed protein source. The quantifi cation of the non-adsorbed enzyme, using Lowry’smethod was used to determine the immobilization rate. The effect of the contact time and the temperature was tested,and 30 min at 250C was considered the best condition for immobilizing papain in both supports. AC showed muchhigher immobilization rates (from 95% to 99%) than AL (from 4% to 13%). The reusability of papain was evaluated bymeasuring the residual activity of the enzyme after it has been used for up to 20 times. The quantifi cation of exposurerate of phenylalanine by second derivative spectrophotometry was used to determine the enzyme activity. In this case, ALshowed better results than AC, since the activity of papain remained unchanged after 15 and 5 times, respectively.Con la intención de preparar suplementos dietéticos de bajo coste, se inmovilizó papaína en carbón activado (CA) yen alúmina, utilizando suero como fuente de proteínas hidrolizadas. Para determinar el índice de inmovilización secuantifi caron las enzimas no adsorbidas mediante el método de Lowry. Se analizó el efecto del tiempo de contactoy la temperatura, considerándose 30 min. a 25 ºC como la condición óptima para inmovilizar la papaína en ambossoportes. El CA presentó unos índices de inmovilización muy superiores (entre 95% y 99%) a los de la AL (entre4% y 13%). Para evaluar la capacidad de reutilización de la papaína se midió la actividad residual de la enzimadespués de haber sido utilizada hasta 20 veces. Para determinar la actividad de la enzima se cuantifi có el índice deexposición de la fenilalanina mediante espectrofotometría de derivada segunda. En este caso, la AL presentó mejoresresultados que el CA, ya que la actividad de la papaína seguía siendo la misma después de haber sido utilizada 15y 5 veces, respectivamente

Peanut cake concentrations in massai grass silage

ABSTRACT Objective. This experiment was conducted to evaluate the best concentration of peanut cake in the ensiling of massai grass of the chemical-bromatological composition, fermentative characteristics, forage value rate, ingestion estimates, and digestibility of dry matter in the silage. Materials and methods. The experiment was carried out at the Experimental Farm of São Gonçalo dos Campos at the Federal University of Bahia, Brazil. The treatments consisted of massai grass that was cut at 40 days and dehydrated, in addition to 0%, 8%, 16%, and 24% peanut cake in the fresh matter and treatment without cake. The material was compressed in experimental silos (7 liter) that were opened after 76 days. Results. The addition of 8-24% peanut cake improved the silage’s chemical-bromatological parameters, increased the dry matter and non-fiber carbohydrates and reduced the fibrous components. There was a linear increase in the estimated values of digestibility and the ingestion of dry matter depending on the levels of peanut cake in the silage. There was an improvement in the fermentative characteristics, with a quadratic effect positive for levels of ammoniacal nitrogen. The forage value rate increased linearly with the inclusion of peanut cake. Conclusions. The inclusion of up to 24% peanut cake during ensiling of massai grass increases the nutritive value of silage and improves fermentation characteristics

Multiple effects of toxins isolated from Crotalus durissus terrificus on the hepatitis C virus life cycle

Hepatitis C virus (HCV) is one of the main causes of liver disease and transplantation worldwide. Current therapy is expensive, presents additional side effects and viral resistance has been described. Therefore, studies for developing more efficient antivirals against HCV are needed. Compounds isolated from animal venoms have shown antiviral activity against some viruses such as Dengue virus, Yellow fever virus and Measles virus. In this study, we evaluated the effect of the complex crotoxin (CX) and its subunits crotapotin (CP) and phospholipase A2 (PLA2-CB) isolated from the venom of Crotalus durissus terrificus on HCV life cycle. Huh 7.5 cells were infected with HCVcc JFH-1 strain in the presence or absence of these toxins and virus was titrated by focus formation units assay or by qPCR. Toxins were added to the cells at different time points depending on the stage of virus life cycle to be evaluated. The results showed that treatment with PLA2-CB inhibited HCV entry and replication but no effect on HCV release was observed. CX reduced virus entry and release but not replication. By treating cells with CP, an antiviral effect was observed on HCV release, the only stage inhibited by this compound. Our data demonstrated the multiple antiviral effects of toxins from animal venoms on HCV life cycle

Peanut cake concentrations in massai grass silage

Objective. This experiment was conducted to evaluate the best concentration of peanut cake in the ensiling of massai grass of the chemical-bromatological composition, fermentative characteristics, forage value rate, ingestion estimates, and digestibility of dry matter in the silage. Materials and methods. The experiment was carried out at the Experimental Farm of São Gonçalo dos Campos at the Federal University of Bahia, Brazil. The treatments consisted of massai grass that was cut at 40 days and dehydrated, in addition to 0%, 8%, 16%, and 24% peanut cake in the fresh matter and treatment without cake. The material was compressed in experimental silos (7 liter) that were opened after 76 days. Results. The addition of 8-24% peanut cake improved the silage´s chemical-bromatological parameters, increased the dry matter and non-fiber carbohydrates and reduced the fibrous components. There was a linear increase in the estimated values of digestibility and the ingestion of dry matter depending on the levels of peanut cake in the silage. There was an improvement in the fermentative characteristics, with a quadratic effect positive for levels of ammoniacal nitrogen. The forage value rate increased linearly with the inclusion of peanut cake. Conclusions. The inclusion of up to 24% peanut cake during ensiling of massai grass increases the nutritive value of silage and improves fermentation characteristics.Objetivo. Este experimento se realizó para evaluar el mejor nivel de inclusión de harina de cacahuete en el ensilado de hierba massai a través de la composición química-bromatológica, las características fermentativas, la tasa de valor forrajero, las estimaciones de la ingestión y la digestibilidad de la materia seca. Materiales y métodos. El experimento se llevó a cabo en la Granja Experimental de São Gonçalo dos Campos, en la Universidad Federal de Bahía. Los tratamientos fueron hierba massai cortada a 40 días, deshidratada, además de un 8%, 16% y 24% de harina de maní en la materia fresca, además de tratamiento sin harina de cacahuete. El material se comprimió en silos experimentales que se abrieron después de 76 días. Resultados. La adición de harina de cacahuete 24% mejor que el ensilaje de productos químicos bromatológicos parámetros, el aumento de la materia seca y carbohidratos sin fibra, y la reducción de los componentes fibrosos. Hubo un aumento lineal de los valores estimados de la digestibilidad y la ingestión de materia seca en función de los niveles de harina de cacahuete en el ensilaje. Se observó una mejoría en las características fermentativas, con un efecto de segundo grado para los niveles de nitrógeno amoniacal. La tasa de valor forrajero aumentó linealmente con la inclusión de harina de cacahuete. Conclusiones. La inclusión de hasta un 24% de harina de cacahuete durante el ensilaje de pasto massai aumenta el valor nutritivo del ensilaje y mejora las características de la fermentación