To isolate and characterize the bacteriocin-producing bacteria (BPB) from the gastrointestinal tract of broiler chickens for probiotic use. In total, 291 bacterial strains were isolated from broilers and screened for bacteriocin-producing ability. The bacteriocins produced by Enterococcus faecium SH 528, Ent. faecium SH 632 and Pediococcus pentosaceus SH 740 displayed inhibitory activity against pathogens including Clostridium perfringens and Listeria monocytogenes. Activity of the bacteriocins remained unchanged after 30 min of heat treatment at 60 degrees C or exposure to organic solvents, but diminished after treatment with proteolytic enzymes. PCR was used to detect the structural genes enterocin A and B in SH 528, enterocin L50 and P in SH 632, and pediocin PA-1 in SH 740. Most of them were resistant to 0.5% bile salts and remained viable after 2 h at pH 3.0. Ent. faecium SH 528 exhibited the highest amylase activity among the strains tested. We selected Ent. faecium SH 528 and SH 632 and Ped. pentosaceus SH 740 by probiotic selection criteria including inhibition activity against pathogens. The isolated BPB could potentially be used in the poultry industry as probiotics to control pathogens.