The First Report Of Bacteriocin Production By The Bacillus Coagulans Is2 And Its Antibacterial Effects

BACILLUS coagulans is a probiotic bacterium with high beneficial effects on human health. The present research was performed to assess the antimicrobial effects of bacteriocin extracted from B. coagulans IS2 against different food-borne bacteria. B. coagulans IS2 was cultured on tryptic soy broth and incubated for 24 h at 37 degrees C. Then, bacteria were sub-cultured on Man, Rogosa, Sharpe (MRS) broth. Produced bacteriocin was extracted from the MRS culture of B. coagulans IS2 by 70% ammonium sulphate. Escherichia coli, Salmonella enterica, and Listeria monocytogenes were cultured on Mueller Hinton Agar. Then, two separate 6 mm wells were created and filled with 200 mu L of extracted bacteriocin. Presence of growth inhibition zones around wells weas considered as antimicrobial effect. The molecular weight of the bacteriocin was assessed by the Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The SDS-PAGE analysis showed presence of low molecular weight protein (<10 KD) in the gel which confirm the presence of bacteriocin-type protein. Clear growth inhibition zones were occurred around the wells contained bacteriocin for all E. coli, S. enterica, and L. monocytogenes bacteria which can directly confirmed the antimicrobial effects of bacteriocin produced by B. coagulans IS2 toward E. coli, S. enterica, and L. monocytogenes. However, it is an introductory work but our findings show an extracted bacteriocin had antimicrobial effects toward both Gram-negative (E. coli and S. enterica) and Gram-positive (L. monocytogenes) bacteria. Nevertheless, additional investigates should perform to found more information about the antimicrobial effects of bacteriocin produced by the B. coagulans IS2.