An analysis of probiotic bacteria's ability to produce biological preservatives and the determination of their minimal inhibitory concentrations

Abstract

Food safety is enhanced by the use of antimicrobials that prevent or delay spoilage and ensure widespread use of pesticides with drawbacks such as increased costs, concerns about food residues and toxins. This study evaluated the production capacity of antimicrobial proteins by two Enterococcus strains (Enterococcus faecalis and Enterococcus hirae). After the cultures of Enterococcus faecalis and Enterococcus hirae in BHI agar medium, the antimicrobial compounds of the strains were purified by dialyzing, and the amount of produced protein was determined by a Lowry test. Further, SDS-PAGE electrophoresis was used to estimate molecular weight. The well-diffusion method was used to test the antimicrobial properties of the compounds studied. Before and after dialysis, factors related to protein activity were determined. Additionally, compounds were evaluated for their minimum inhibitory concentrations. The results show that the most antimicrobial effect of antimicrobial species on the Bacillus cereus and more antimicrobial effects on the hirae species on Staphylococcus aureus.

Keywords:
Enterococcus faecalis; Enterococcus hirae; antimicrobial proteins; biological preservatives