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

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

Mar del Plata

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

ASOCIACION ARGENTINA DE FARMACOLOGIA EXPERIMENTAL

The use of Probiotics in Intensive Steers Systems (ISS) has emerged as analternative to decrease antibiotic application. NewProbioticFormulas 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 bacterialsurface properties to promote the adhesion, biofilm formation and colonization to the host must be evaluated for the selection of probiotic strains. Our research group is working on the design of a probiotic formula for bovine feedlot,then around 500 strains werepreviously isolated, 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 hydrophobicity and Biofilm Formation(BF) were evaluated. The hydrophobic nature of the cell surface was determined by the MATH (microbial adhesion to hydrocarbons: toluene and xylene) method.The extent of aggregation was studied by the decrease of optical density of cell suspensions. BFwas assayed by the crystal violet-stained methodinMRS 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. Highaggregation patters were observed in5% of the LABs. There was a correlation between the two surface properties in L mucosaeCRL2069 and CRL2115. The strains showing BF in MRS were: L mucosaeCRL2083 and CRL2063; and in MRS-T: EfaeciumCRL2141, EhiraeCRL2062, L mucosaeCRL2101 and CRL2112, andLfermentumCRL2085. 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 further evaluated for the design of a probiotic formulation for ISS.