摘要：During the recent years, production of antimicrobial substances by Bacillus strains have been attracted due to their broad antimicrobial spectrum. In the current study, some Bacillus strains which were previously isolated from some fermented foods as well as soil have been screened for antimicrobials production. Six of the isolates have been detected as antimicrobial substance producers. Antimicrobial activity was determined using disc diffusion assay against eight important food pathogens (Bacillus cereus, Escherichia coli O157:H7, E. coli, Listeria monocytogenes, Salmonella Enteritidis, Salmonella Typhimurium, Staphylococcus aureus. and Pseudomonas aeruginosa). The cell-free supernatants of the isolates used in current study did not inhibit the growth of S. aureus, however all inhibited E. coli O157:H7. The results showed that their antimicrobial spectrums were broad including both Gram negative and Gram positive bacteria. All the isolates produced the maximum amount of antimicrobials at 24 h and increased incubation periods caused the decrease in the production of antimicrobials.
