Efecto del tipo de sustrato sobre la digestibilidad in vitro de la proteína de extractos generados por Saccharomyces cerevisiae
Efecto del tipo de sustrato sobre la digestibilidad in vitro de la proteína de extractos generados por Saccharomyces cerevisiae
Authors
Velásquez Briceño, Alejandro
Arias Inostroza, Rodrigo
Arias Inostroza, Rodrigo
Authors
Date
2015-07-22
Datos de publicación:
Ciencia e investigación agraria, Vol.40, N°3, 503-511
Keywords
Saccharomyces cerevisiae - Sustratos vegetales - Digestibilidad in vitro
Collections
Abstract
Se evaluó el efecto del tipo de sustrato a fermentar por Saccharomyces cerevisiae (Sc) sobre la digestibilidad in vitro de la proteína cruda (Divcp y Div2h), de la proteína verdadera (Dtp) y la tasa de degradación de proteína (kdcp) en diferentes extractos proteicos producidos por esta levadura. Estos fueron generados a través de un método biotecnológico (fermentación en estado sólido). Se utilizaron como sustratos (tratamientos del experimento) paja de trigo, TWS; paja de cebada, TBS; rastrojo de ají, TCS; cascara de avena, TOH y almidón-glucosa en polvo, TSP (control). Para el cultivo de Sc con los sustratos a evaluar, se agregaron 2 mL de una solución de inóculo de Sc (6,7×106 sporas mL-1) a 12 mL de medio de cultivo, junto con 2 g de sustrato vegetal (materia seca), más una fuente de nitrógeno. La incubación fue mantenida por 7 días bajo condición aeróbica, a una temperatura constante de 26 °C (pH 5). El contenido promedio de PC de la biomasa de levadura generada fue de 45%. Luego de realizar la extracción de la biomasa de Sc, se midió la digestibilidad in vitro de sus proteínas en dos fases (pepsina/tripsina-pancreatina). Los resultados permitieron observar un efecto del tipo de sustrato fermentado (P≤0,001) sobre la Divcp y Dtp (P≤0,01). La mayor digestibilidad (Divcp) fue obtenida con TSP (78,9% PC) y la menor con TCS (67,1% PC). También, se pudo apreciar diferencias entre los tratamientos (P≤0,01) para la velocidad de degradación (kdcp). La medición de un 71,8% (promedio) para Divcp, 16,4% h-1 (promedio) para kdcp, y un contenido satisfactorio de PC, permiten sugerir que este extracto de Sc posee el potencial para llegar a constituir una alternativa como suplemento proteico para nutrición animal.
The in vitro crude protein (CP) digestibility (Divcp), true protein digestibility (Dtp) and degradation rate (kdcp) were measured in different protein extracts of Saccharomyces cerevisiae (Sc) yeast. These extracts were generated through a biotechnological method (solid state fermentation). Wheat straw (TWS), barley straw (TBS), chili stubble (TCS), oats hull (TOH) and starch-glucose powder (TSP; control) were used as substrates for fermentation by Sc, and their effect on the aforementioned kinetic parameters in the generated cellular biomass was evaluated. In 12 mL cultivation medium, 2 mL Sc solution inoculum (6.7×106 spores mL-1) was added together with 2 g vegetable substrate (dry) and additional nitrogen source, and the mixture was incubated for 7 days at a constant temperature (26°C at pH 5) under aerobic conditions. The average CP content of the yeast biomass (DM) was of 45%. The Divcp and Dtp were analyzed (two phases: pepsin/trypsin-pancreatin) after the extraction of the yeast biomass, and an effect of the fermented substrate on these values (P≤0.001 and P≤0.01, respectively) was observed. The greatest digestibility (Divcp) was obtained with TSP (78.9% CP) and the lowest with TCS (67.1% CP). In addition, differences in the kdcp between the treatments were also observed (P≤0.01). The high contents of CP, Divcp (71.8% on average) and kdcp (16.4% h-1 on average) suggest that Sc yeast biomass has the potential to become an alternative for the production of animal protein supplements.
The in vitro crude protein (CP) digestibility (Divcp), true protein digestibility (Dtp) and degradation rate (kdcp) were measured in different protein extracts of Saccharomyces cerevisiae (Sc) yeast. These extracts were generated through a biotechnological method (solid state fermentation). Wheat straw (TWS), barley straw (TBS), chili stubble (TCS), oats hull (TOH) and starch-glucose powder (TSP; control) were used as substrates for fermentation by Sc, and their effect on the aforementioned kinetic parameters in the generated cellular biomass was evaluated. In 12 mL cultivation medium, 2 mL Sc solution inoculum (6.7×106 spores mL-1) was added together with 2 g vegetable substrate (dry) and additional nitrogen source, and the mixture was incubated for 7 days at a constant temperature (26°C at pH 5) under aerobic conditions. The average CP content of the yeast biomass (DM) was of 45%. The Divcp and Dtp were analyzed (two phases: pepsin/trypsin-pancreatin) after the extraction of the yeast biomass, and an effect of the fermented substrate on these values (P≤0.001 and P≤0.01, respectively) was observed. The greatest digestibility (Divcp) was obtained with TSP (78.9% CP) and the lowest with TCS (67.1% CP). In addition, differences in the kdcp between the treatments were also observed (P≤0.01). The high contents of CP, Divcp (71.8% on average) and kdcp (16.4% h-1 on average) suggest that Sc yeast biomass has the potential to become an alternative for the production of animal protein supplements.