Resumen de Identificación preliminar in vitro de propiedades probióticas en cepas de "S. cerevisiae"

Ana Rubio M., María Hernández E., Andrea Aguirre R., Raúl Poutou Piñales

• español

  Objetivo. Evaluar preliminarmente in vitro algunas propiedades probioticas de dos cepas nativas de S.cerevisiae. Materiales y metodos. Las cepas fueron utilizadas en ensayos de tolerancia a sales biliares, pH, temperatura, adherencia a Salmonella spp., E.coli y Shigella spp., y antagonismo. Se realizo un diseno factorial 33 x 3, con tres niveles de cada factor (cepa, pH y concentracion inicial de sustrato) por triplicado, para establecer las condiciones de cultivo de cada cepa. Como control se empleo una cepa comercial (B). La cepa seleccionada se empleo para la produccion en biorreactor de 2L; la biomasa fue sometida a secado por temperatura; al producto resultante se le determino concentracion de N2 y la viabilidad celular. Resultados. La cepa A (obtenida de cana de azucar), tolero pH 3 �} 0.2, 0.3% (p/v) de sales biliares y 42oC. El ANOVA del diseno factorial reporto diferencias significativas entre los 27 ensayos (p.0.05), el analisis de superficies reporto que la interaccion entre los factores cepa y Sustrato (S0) son significativos, sugiriendo para la optimizacion la cepa A y concentraciones crecientes de S0. Los resultados se reprodujeron en biorreactor con mx 0.31h-1, td 2.18h y Y(x/s) 0.126g/g; la biomasa seca obtenida fue viable y reporto entre 6.3 y 6.9% N2/g. Conclusiones. Se identificaron levaduras nativas con propiedades probioticas como tolerancia a pH, sales biliares, temperatura y adherencia a Salmonella spp., E.coli y Shigella spp.

• English

  Objective. To evaluate probiotic properties of two native strains of S. cerevisiae. Materials and methods. Strains were used in assays for tolerance to biliary salts, pH, temperature and adhesion to Salmonella spp., E. coli and Shigella spp. and antagonism. A 33 x 3 factorial design was used, with three levels for each factor (strains, pH and initial concentration of substrate (S 0 )) by triplicate, to establish the culture conditions for each strain. A commercial strain (B) was used as control. The selected strain was cultured in a 2L bioreactor; the biomass was dryed by temperature and the resulting product was assayed to determine N 2 concentration and cellular viability. Results. Strain A (from sugar cane), tolerated pH 3 ± 0.2, 0.3% (w/v) of biliary salts and 42°C. The factorial ANOVA found significant differences between the 27 assays (p<0.05) and surface analysis found that the interaction between factors strain and S 0 was significant, suggesting for the optimization process the use of strain A and increasing concentrations of S 0 . Results were reproduced in bioreactor with mx 0.31h-1, dt 2.18h and Y(x/s) 0.126g/g. the dry biomass obtained was viable and yielded between 6.3 and 6.9% N2/g. Conclusions. Native strains were identified with probiotic properties such as pH, biliary salt and temperature tolerance, and adherence to Salmonella spp., E .coli and Shigella spp.