Growth (OD₆₀₀) of selected lactic acid-producing bacterial isolateswith or without pretreatment of low pH^*.

*Tolerance to low pH was evaluated by incubating bacterial cells in simulated gastric fluid (pH 2.0 or 5.6) for 2 h prior to anaerobic incubation in the MRS broth at 37°C for 20 h.Values without common superscript in a row are significantly different (P<0.05). Values were average of triplicates. #The 14 selected lactic acid-producing bacterial isolates belong to Lactobacillus crispatus (SG2), Lactobacillus plantarum (S8 and S66), Lactobacillus salivarius (ALB2 and ALB6), Lactobacillus reuteri (CL9, K67, and S64), Lactobacillus rhamnosus (L3, LB2, and LB4), Lactobacillus zeae (LB1), and Pediococcus pentosaceus(K16 and S33), based on the sequence analysis of 16S rRNA genes. While isolates ALB2, ALB6, L3, LB1, LB2, LB4, and SG2are from chickens, isolates CL9, K16, K67, S8, S33, S64, and S66 have the pig origin.