Abstract: It was to investigate the viability of Saccharomyces boulardii, Bacillus licheniformis and Lactobacillus plantarum in the acidic and bile salts conditions, three potentially probiotic role with the two pathogens E. coli and Staphylococcus aureus verify three probiotic antagonistic pathogens ability. The acidic and Bile salts conditions tolerance of the three potentially probiotic were determined by exposing washed cell suspensions to acidic conditions（pH1.0, 2.0, 3.0, 4.0 and 5.0）and different bile salts concentration[0%, 0.05%, 0.1%, 0.2%, 0.3%（W/V）]of physiological saline for 1, 2, 3 and 4 hours, reseparately, then three potentially probiotic separately with two pathogens 37℃ static co-culture 4 h, plate colony counting method for the determination of the probiotic viable cells. Result showed that Lactobacillus plantarum acid resistance is the most obvious, the Saccharomyces boulardii and Bacillus licheniformis also has good acid resistance. Bacillus licheniformis bile salts tolerance is the most obvious, the Lactobacillus plantarum and Saccharomyces boulardii also has good resistance to bile salts. These studies suggested that the three potentially feed probiotic have certain acid and bile tolerance capacity, possibly have a prebiotic effect in piglets role by antagonizing pathogens.

Key words: Probiotics, Acid resistance, Concentration of bile tolerance, Antagonistic