Surface properties of lactic acid bacteria for the design of a probiotic formula for bovine feed-lot.

FLAVIA IVANA MANSILLA; NATALIA CECILIA MALDONADO; CECILIA ARISTIMUÑO FICOSECO; CONSTANZA MELIAN; GRACIELA VIGNOLO; MARIA ELENA FÁTIMA NADER

Mar del Plata

Congreso; XLVIII REUNION ANUAL DE LA ASOCIACION ARGENTINA DE FARMACOLOGIA EXPERIMENTAL (SAFE); 2016

SAFE-SAI-SAIC

The use of Probiotics in Intensive Steers Systems (ISS) has emerged as an alternative to decrease antibiotic application. New Probiotic Formulas are being designed in Pharmaceutical and Food fields for human and animal health, by using bacteria isolated from the indigenous microbiota of the specific host. The screening of the bacteria surface properties to promote the adhesion, biofilm formation and colonization is must be evaluated for the selection of probiotic strains. Our research group is working on the design of a probiotic formula for bovine, and 500 strains were isolated from feedlot, identifying 72 lactic acid bacteria (LAB) by genetic tools. The aim of this work was to perform the screening of the surface properties of the LAB, identified into the Enterococcus, Lactobacillus, Pediococcus and Weissella genera. Autoaggregation, surface hidrophobicity and Biofilm Formation (BF) were evaluated. The hydrophobic nature of the cell surface was determined by the microbial adhesion to hydrocarbons (toluene and xylene) method. The extent of aggregation was studied by the optical density of cell suspensions. BF was assayed by the crystal violet-stained method in MRS media with and without Tween 80 (MRS-T). The results obtained indicate that most of the strains (85% and 82%) show a low degree of hydrophobicity (0-30%) in toluene and xylene, respectively. High aggregation patters were observed in 5% of the LABs. There was a correlation between the 2 surfaces properties evaluated in L mucosae CRL2069 and CRL2115. The strains showing BF in MRS were: L mucosae CRL2083 and CRL2063; and in MRS-T: E faecium CRL2141, E hirae CRL2062, L mucosae CRL2101 and CRL2112, and L fermentum CRL2085. From the results obtained, the strains selected were: CRL2141 (high BF and hydrophobicity) and CRL2069 (high aggregation and hydrophobicity). The screening performed allowed to select strains expressing surface properties to be evaluated for the design of a probiotic formulation for ISS.