Milk-clotting proteases from Pleurotus albidus: an innovative alternative for the production of Minas frescal cheese

Pleurotus albidus, a naturally growing species in the Amazon region, has been considered a promising source of milk-clotting proteases. The production of such enzymes using lignocellulosic residues is a sustainable alternative to replace mammalian rennet. The application of P. albidus milk-clotting proteases in cheese making has not yet been reported in the scientific literature. The aim of this study was to characterize the milk-clotting proteases of P. albidus and use these enzymes in the production of Minas frescal cheese. For the production of coagulating proteases, the mushroom was grown in açaí seeds supplemented with rice bran (10%, w/w). The parameters affecting the production of coagulant, such as inoculum size, fermentation time, initial pH of cultivation medium and age of the inoculum were evaluated. The coagulant extract obtained under optimal production conditions was evaluated for optimal pH and temperature, pH and temperature stability, effect of ions and inhibitors. Significant production of coagulating proteases was obtained under the following conditions: inoculum size (2.5%), fermentation time (10 days), initial pH of the cultivation medium (6), and inoculum age (10 days). The coagulant exhibited significant catalytic activity in pH 5.0 at 55°C, with stability at 45°C and was completely inhibited by iodoacetic acid. The milk-clotting proteases of P. albidus were efficient for making Minas frescal cheese that presented 55.0% of moisture, 20.0% of lipids and 17.20% of protein. Pleurotus albidus is a potential source of milk-clotting proteases that can be applied in dairy industry for production of fresh Minas frescal cheese.

Effects of pH, Temperature and Agitation on the Decolourisation of Dyes by Laccase-Containing Enzyme Preparation from Pleurotus sajor-caju

(1) Background: In this study, the effects of different pH values ​​(2.4, 3.2, 4.4 and 5.0), temperatures (30, 35, 40, 45 and 50°C) and agitation (100 rpm) on the enzymatic decolourisation of twenty-two dyes belonging to the chromophore groups anthraquinone, azo and triphenylmethane were assessed. (2) Methods: In all conditions, it was used a crude enzyme broth containing 30 U mL-1 laccases produced by Pleurotus sajor-caju PS-2001 in submerged process. (3) Results: Regarding the effects of pH values, the best results were obtained at pH 3.2 and 30°C, in which bleaching was observed for all dyes evaluated. In assays conducted at different temperatures, highest levels of decolourisation were observed at 35°C and pH 3.2 for nineteen of the dyes assessed. Thirteen dyes presented colour reduction exceeding 50% after the enzymatic treatment, including all acid and all disperse dyes evaluated. The reciprocal agitation of 100 rpm promoted negative effect on decolourisation. (4) Conclusion: From the results achieved, one can conclude that the laccase-containing preparation of P. sajor-caju PS-2001 has potential for the decolourisation of some dyes widely used in different industrial sectors, especially in the textile industry, and therefore could be used in future strategies for the biotreatment of coloured wastes.

Extraction and in vitro antioxidant activity of exopolysaccharide by Pleurotus eryngii SI-02

The extraction parameters for Pleurotus eryngii SI-02 exopolysaccharide (EPS) produced during submerged culture were optimized using response surface methodology (RSM). The optimum conditions for EPS extraction were predicted to be, precipitation time 20.24 h, ethanol concentration 89.62% and pH 8.17, and EPS production was estimated at 7.27 g/L. The actual yield of EPS under these conditions was 7.21 g/L. The in vitro antioxidant results of the EPS showed that the inhibition effects of EPS at a dosage of 400 mg/L on hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were 59.63 ± 3.72%, 38.69 ± 2.59%, and 66.36 ± 4.42%, respectively, which were 12.74 ± 1.03%, 8.01 ± 0.56%, and 12.19 ± 1.05% higher than that of butylated hydroxytoluene (BHT), respectively. The reducing power of EPS of P. eryngii SI-02 was 0.98 ± 0.05, 60.66 ± 5.14% higher than that of BHT. The results provide a reference for large-scale production of EPS by P. eryngii SI-02 in industrial fermentation and the EPS can be used as a potential antioxidant which enhances adaptive immune responses.

Contenido de fenoles totales en extractos de Pleurotus obtenidos con solventes de diferente polaridad / Content of total phenols in Pleurotus sp. extracts obtained with solvents of different polarity

Introducción: Los hongos comestibles han sido utilizados desde tiempos inmemoriales por sus propiedades nutricionales y farmacológicas. Objetivo: Con el objetivo de desarrollar en Cuba nuevas formulaciones de valor terapéutico a partir de Pleurotus, han sido investigados los efectos inmunomoduladores de tres preparaciones de cuerpos fructíferos. Métodos: En la investigación se pudo determinar el contenido de fenoles totales en 5 extractos de cuerpos fructíferos de setas comestibles tipo Pleurotus sp. obtenidos con solventes de diferente polaridad: n-hexano, acetato de etilo, acetona, etanol y agua. La determinación del contenido de polifenoles se realizó con el reactivo de Folin-Ciocalteu. Los datos relacionados con el contenido de sólidos totales en los extractos fueron procesados mediante un análisis de varianza (ANOVA) de clasificación simple. Resultados: La concentración de sólidos totales resultó superior en los extractos acuoso y etanólico, con valores tres y cinco veces mayores con respecto a los alcanzados con solventes menos polares (p< 0,05). En los cinco extractos se detectaron compuestos fenólicos; sin embargo, los niveles más elevados se encontraron en aquellos obtenidos con los solventes más polares (agua y etanol) con valores de 138,4 y 86,37 mg/100 g, base seca, respectivamente (p< 0,05). Se constató la existencia de una correlación positiva entre el contenido de fenoles y la constante dieléctrica de los solventes (r= 0,92). Conclusiones: Los resultados sugieren la evaluación de la actividad antioxidante de las fracciones polares de cuerpos fructíferos de Pleurotus en modelos in vitro e in vivo

Background: Edible mushrooms have been used since the immemorial because of their nutritional and pharmacological properties. Objective: Immunomodulating effects of three preparations of fruit bodies have been investigated with the aim of developing new formulations of therapeutic value from Pleurotus in Cuba. Methods: In this research, the content of total phenols was determined in five extracts of fruit bodies of Pleurotus sp. mushrooms, obtained with solvents of different polarity: n-hexan, ethyl acetate, acetone, ethanol and water. The content of polyphenols was determined using the Folin-Ciocalteu reagent. The data related to the content of total solids in the extracts were processed by a simple analysis of variance (ANOVA). Results: The concentration of total solids was higher in the aqueous and ethanolic extracts, with three and five times higher values than the ones obtained with less polar solvents (p<0.05). Phenolic compounds were detected in the five extracts; however, the highest levels were found in those obtained with the most polar solvents (water and ethanol) with values of 138.4 and 86.37 mg/100 g, dry base, respectively (p< 0.05). A positive correlation between the phenol contents and the solvent dielectric constant was observed (r= 0.92). Conclusions: The results suggest the evaluation of the antioxidant activity of the polar fractions of fruit bodies of Pleurotus both in in vitro and in vivo models

Influencia del sustrato utilizado para el crecimiento de hongos comestibles sobre sus características nutraceúticas / The influence of the substrate used for growing edible fungi on their nutraceutic characteristics

Siendo Colombia un país en el cual hay un gran desarrollo de la actividad agraria, generadora de cantidades apreciables de desechos que dan lugar a un problema ambiental, el cultivo de los hongos presenta un potencial en aplicaciones biotecnológicas que derivan de la diversidad metabólica de los mismos. Dicho potencial está tanto en la producción de los hongos como alimentos con óptimas calidades nutricionales, como en la obtención a partir de las setas de productos bioactivos que permitirían en un futuro no muy lejano contribuir a la economía del país y a la descontaminación ambiental. Dentro del reino fungi, las especies de Pleurotus pueden crecer sobre una amplia variedad de sustratos y tienen especiales propiedades para degradar los componentes lignocelulósicos presentes en mayor proporción en los residuos de la agroindustria. El objetivo del presente estudio fue el de evaluar el efecto del sustrato sobre las propiedades nutricionales o nutriceúticas de hongos del género Pleurotus. Como resultado se determinó que efectivamente la composición de los hongos en cuanto al contenido de proteínas netas, fibra, humedad, cenizas, carbohidratos y grasas totales varía con el sustrato empleado, lo que incide directamente en las propiedades antes anotadas, si se tiene en cuenta que dentro de los componentes determinados se encuentran metabolitos como polisacáridos y esteroles con bioacciones previamente reportadas. De igual manera, se encontró que estas variaciones son diferentes dependiendo de la especie.

Being Colombia a country in which there is a great development of the generating agrarian activity of appreciable quantities of waste that they give place to an environmental problem, the cultivation of the mushrooms presents a potential in biotechnical applications that derive of the metabolic diversity of the same ones. This potential is in the production of the mushrooms like in foods with good nutritional qualities. For instance in the obtaining starting from the mushrooms of bioactive products that would not allow in a very distant future to contribute to the economy of the country and the environmental decontamination. Inside the fungi Kingdom, the Pleurotus species can grow about a wide substrate variety and they have special properties to degrade the lignocelulosic component present in bigger proportions in the residuals of the agroindustry. The objective of the present study was of evaluating the substrate effect on the nutritional and/or nutriceutical quality of mushrooms of the Pleurotus gender. As a result it was determined that indeed the composition of the mushrooms as for the content of net proteins, fiber, humidity, ashes, carbohydrates and total fats, varies with the substrate used, what impacts directly in their properties, taking into account that in certain components are metabolites such as polysaccharides and sterols with bioactions previously reported. Similarly it was found that these variations are different depending on the species.

Calidad proteínica de tres cepas mexicanas de setas (Pleurotus ostreatus) / Protein quality of Mexican Pleurotus ostreatus strains

Se evaluó la calidad proteínica de los cuerpos fructíferos de tres cepas mexicanas de Pleurotus ostreatus (INIREB-8, CDBB-H-896 y CDBB-H-897), cultivadas en invernadero, temperatura registrada de: 22-28 grados Celsius y 75-85 por ciento de humedad relativa, en paja de trigo como substrato. La concentración de proteína (Nx4.38), osciló entre 17.26 y 19.97 g/100g en peso seco. Sus puntajes químicos estuvieron entre 74 a 93 por ciento la lisina disponible el primer aminoácido limitante para las cepas INIREB-8 y CDBB-H-896 y la leucina para la CDBB-H-897. Los valores de digestibilidad in vitro fueron de: 67.75-68.38 por ciento. El valor protínico relativo varió de 100.06 a 107.85 por ciento, siendo menor que el del frijol soya cocido y huevo entero; e iguales estadísticamente a los de la leche descremada en polvo, caseína más metionina y albúmina; y superiores a los del arroz, maíz, frijol, lenteja, haba y pasta para sopa. En función de lo anterior se puede concluir que por su contenido de aminoácidos esenciales, las proteínas de las setas (especialmente la cepa INIREB-8) se complementan adecuadamente con la de los cereales, por lo cual es altamente recomendable incluirlas en la dieta diaria.

Avaliaçäo da composiçäo em aminoácidos de Pleurotus spp. cultivados em folha de bananeira / Amino acid composition evaluation of Pleurotus spp. cultivated in banana leaves

A qualidade da proteína de cogumelos, além de ser específica para a espécie/linhagem, pode variar também com o substrato de cultivo. Esse estudo teve por objetivo determinar a composiçao em aminoácidos da proteína dos cogumelos comestíveis Pleurotus sp. "Florida" (L1), P. ostreatoroseus (L2) e P. sajor-caju (L3), cultivados em folha de bananeira (PB) unicamente e, esta misturada ao bagaço de cana (PBBC). Foram avaliados os aminoácidos totais, cistina e triptofano; calculou-se o escore químico e o PDCAAS- "protein digestibility-correct amino acid scoring". As espécies estudadas apresentaram todos os aminoácidos essenciais, de ambos substratos; os aminoácidos presentes em maiores quantidades foram, em ordem decrescente, ácido glutâmico, ácido aspártico, leucina e lisina. O escore químico da proteína de L1 foi de 90,4, com limitaçao em sulfurados e aromáticos no substrato PB e, no PBBC, o escore químico foi de 88,7 com limitaçao em aromáticos. O escore químico de L2 e L3 foi igual a 100, independente do substrato de cultivo. O PDCAAS calculado, considerando-se 90 por cento de digestibilidade recomendado, variou entre 80,0 a 96 por cento. As proteínas de L1 apresentaram-se limitantes em sulfurados e aromáticos e com menor valor de PDCAAS (approximatelly 80,0) nos dois substratos empregados; a proteína de L3 apresentou limitaçao em aromáticos, sulfurados e triptofano dependendo do substrato de cultivo; as proteínas de L2 apresentaram o maior valor de PDCAAS (96 por cento) e limitaçao em aromáticos e/ou sulfurados, dependendo do substrato de cultivo. Considerando-se as condiçoes desse estudo, a proteína das espécies estudadas é incompleta porém de alto valor biológico, comparáveis às da carne.

Composición química de tres cepas mexicanas de setas (Pleurotus ostreatus) / Chemical composition of three Mexicans strains of Pleurotus ostratus

Se determinó la composición química de tres cepas mexicanas de setas (Pleorotus ostreatus): INIREB-8, CDBB-H-896 y CDBB-H-897, cultivadas en un invernadero (22-28 graus Celsius de temperatura y 80+5 por ciento de humedad relativa), utilizando paja de trigo como substrato. El análisis de los cuerpos fructíferos expresado en g/100 g en peso seco, reveló valores de: Proteína (N x 6.25): 24.64+0.21 - 28.50+0.26; lípidos: 1.10+0.16 - 1.85+0.22; cenizas: 7.66+0.23 - 8.79+0.25; fibra dietética total: 32.14+0.14 - 36.81+0.40; y carbohidratos disponibles: 26.33+1.04 - 30.46+0.21. Se encontraron cantidades significativas de riboflavina: 3.31 - 3.70, tiamina: 1.92 - 1.96, niacina: 35.98 - 36.56 ácido ascórbico 28 - 35, mg/100g en peso seco; los contenidos de calcio y fósforo fueron menos significativos. El contenido de ácido linoleico fue de 0.70 - 1.19 g/100g en peso seco. Se concluye que las setas pueden proporcionar a la dieta algunas vitaminas del complejo B, fibra dietética, proteína y ácido linoleico.