Characterization of a bacteriocin-like substance produced by Bacillus amyloliquefaciens isolated from the Brazilian Atlantic forest.

A Bacillus strain producing a bacteriocin-like substance was characterized by biochemical profiling and 16S rDNA sequencing. Phylogenetic analysis indicated that the strain has high sequence similarity with Bacillus amyloliquefaciens. The antimicrobial substance was inhibitory to pathogenic and food-spoilage bacteria, such as Listeria monocytogenes, Bacillus cereus, Serratia marcescens, and Pasteurella haemolytica. It was stable over a wide temperature range, but lost activity when the temperature reached 121 degrees C/15 min. Maximum activity was observed at acidic and neutral pH values, but not at alkaline pH. The antimicrobial substance was sensitive to the proteolytic action of trypsin, papain, proteinase K, and pronase E. Except for iturins, other antimicrobial peptides have not been described for B. amyloliquefaciens. The identification of a bacteriocin-like inhibitory substance active against L. monocytogenes addresses an important aspect of food protection.