Antimicrobial activity of bacteriocin produced by lactobacillus bacteria against proteus spices

Abstract

Probiotics are from non-pathogenic bacteria that have beneficial effects for their host through producing anti-microbial compounds, such as bacteriocin. Bacteriocins are defined as antimicrobial proteins or peptides that have inhibitory effect. In this study Lactobacillus plantarum (ATCC 8014) and Lactobacillus acidophilus (ATCC 4356) were tested for production of bacteriocins in different pH, temperatures and enzymes treatment, then their activity against Proteus spices as a most common urinary tract infections evaluated. The results demonstrate that the cell-free supernatant from L. plantarum and L. acidophilus is effective in inhibiting the growth of different strains of Proteus. The inhibitory compound lost activity when heated to temperatures greater than 30°C and when subjected to pH changes that lowered the pH below 4 or above 5. In addition, the inhibitory protein was susceptible to digestion by various proteases. These findings support the idea that the inhibitory compounds in both studied stains can be considered as a bacteriocin by relative heat and pH stable and proteiaceous nature that can have inhibitory effect against Proteus spices.