Bacteriocin Production by Lactobacilli and Their Role as Antibacterial Tool against Common Pathogens

Abstract

Lactobacilli are commonly found in raw and fermented foods. These bacteria are of common interest because of their capability of bacteriocin production. Bacteriocins are compounds that may be used as natural preservatives in place of chemical additives. In the present study five different samples of poultry, meat and pickle were used to isolate lactic acid bacteria (LAB) by using the MRS culture medium. Antibacterial activity was checked against Pseudomonas aeruginosa, E. coli and Staphylococcus aureus. Five strains from the poultry meat and six strains from pickle had shown antibacterial activity out of eight strains against pathogenic bacteria. Three strains of poultry meat i.e. M3, M7, M11, had shown antibacterial activity against all three indicator strains. While one strain M1 was active against Pseudomonas aeruginosa and E. coli but it was found not to be active against Staphylococcus aureus. E. coli and Staphylococcus aureus were not susceptible to M2. In the case of pickle strains H1, H2, NAT1, NAT2, were found to be active against Pseudomonas aeruginosa and E. coli but Staphylococcus aureus was not susceptible to bacteriocins of these strains. NAT3 and SHZa strains showed antibacterial activity against all the three used pathogens. The highest activity (6 mm) had shown by the lNAT3 strain of pickle against Pseudomonas aeruginosa. The least antimicrobial activity had shown by SHZa strain. M3 had an inhibition zone of 5 mm against Pseudomonas aeruginosa. M11 had an inhibition zone of 5 mm against E. coli. Bacteriocins of all isolates were sensitive towards enzyme pepsin showing their proteinaceous nature. Detection of the bacteriocin gene by PCR the strains M2, M7 were amplified for Curvacin and plantaricin genes. From current study, it is concluded that different species of Lactobacilli can be used as antibacterial tool against common bacterial pathogens.