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

Abstract

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 °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 104 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.