Bacillus spp. produces a large number of antimicrobial peptides and includes a variety of species
of industrial importance. The aim of this study was to characterize the antimicrobial activity
associated with a Bacillus subtilis strain. The activity of the crude bacteriocin-like substance
(CBLS) was dependent on the components of the culture media and was detected in the exponential
phase of growth. The CBLS was stable at a variable pH range and at 100°C, but it was inactivated
by sterilization conditions. It was also stable to storage at refrigeration and freezing temperatures
for a considerable time. The mode of action of the antimicrobial activity was bacteriostatic
and the effect on the cell membrane was determinated by Fourier transform infrared (FTIR)
spectroscopy.