CONICET | Buscador de Institutos y Recursos Humanos

Probiotics are frequently used for multiple objectives, being the majority of applications performed both in human beings and in different animals. The specificity of species showed by the members of the indigenous microbiotia leads us to isolate lactic acid bacteria from their natural bovine ecosystems, to select those with probiotic potentiality. The isolation and selection of beneficial probiotic lactic acid bacteria was performed from the vaginal tract and mammary gland of adult heifers, and from faeces and oral cavity of newborn calves. The type and number of strains were different according to the tract under study. Their surface properties, evaluated through the MATH test, revealed that the higher number of low hydrophobic strains were isolated from vaginal tract, mammary gland or faeces. The capability of autoaggregation was also different, with higher degree only in those isolated from vagina, while those originated in the mammary gland or faeces showed low autoaggregation characteristics. The production of antagonistic substances showed that the production of hydrogen peroxide was higher in the strains isolated from the vaginal tract, while those able to produce organic acid were isolated from all the environments. A few strains able to produce bacteriocins were isolated only from the mammary gland and faeces, but not from the vaginal tract. Further studies are being performed to complete the functional characterization of the strains directed to determine their survival to the environmental conditions of each tract. Finally, the selected strains can be combined for the design of probiotic products to be used both in adult cows and in neonates, based on the host-specificity, by their autochthonous origin and their potential use in the tract where isolated.