A newly-isolated Bacillus subtilis BSC35 produces bacteriocin-like inhibitory substance with high potential to control Clostridium perfringens in food

Previous studies on Bacillus subtilis-producing bacteriocins (or bacteriocin-like inhibitory substance, BLIS) against Clostridium perfringens provided with limited information to show their potentials. In this study, B. subtilis BSC35 was newly-isolated and its BLIS-containing cell-free supernatant exhibited a strong antimicrobial activity (maximum 24 mm of lysis zone in standard well diffusion assay) against all the tested C. perfringens strains (22 farm isolates and 2 references). The culture condition was optimized (30 degrees C, 240 rpm, TSB at pH 7.5) to maximize BLIS BSC35 production and stability of BLIS BSC35 was tested. After zymogram study following partial purification, BLIS BSC35 was measured approximately 4 kDa in size. Finally, when cell-free-supernatant or B. subtilis BSC35 culture was used to control C. perfringens in liquid medium and a food model (Cheonggukjang), as low as 0.1% and 10 4 CFU/g addition, respectively, was enough to strongly inhibit the growth of C. perfringens with a rapid bactericidal mode of action, implying high anti-C. perfringens potentials and wide range of applicabilities.

Automated summary

This study identified a newly isolated B. subtilis BSC35 with strong antimicrobial activity against C. perfringens, highlighting the potential of BLIS as an effective inhibitor of this pathogen under optimized culture conditions.