Determination of Molecular Weight and Antimicrobial Activities of a Purified Bacteriocin from Lactiplantibacillus plantarum MDP 5
Nowadays, unlimited use of antibiotics and preservatives have become a big concern regarding the human health which turn the interest of biotech industries into their research on biologically active molecules from probiotic microbes, since they are nontoxic and suitable for many safer applications. On this background, the present investigation focused on the characterization of a bacteriocin from a Lactobacillus strain. The characterization of a bacteriocin was done using a Lactiplantibacillus plantarum MDP 5 isolated from the local markets of Puducherry and production was performed under standardized cultural conditions. The study on the maximum recovery of bacteriocin using ammonium sulphate precipitation method revealed that the 60% saturation rate evidenced highest activity of 6500 AU/ml with 4.113g/L dry weight followed by the purification was done with RP-HPLC method using C18 column. The purified bacteriocin revealed a novel molecular weight of 22 kDa with the help of SDS-PAGE which has not been reported from Lactobacillus species. Further, the purified bacteriocin evidenced appreciable antimicrobial activities against all the tested human bacterial pathogens of this study. The highest antimicrobial activity was recorded against Escherichia coli MTCC 443 followed by Staphylococcus aureus MTCC 96, Vibrio parahemolyticus MTCC 451, Enterococcus faecalis MTCC 9845, Pseudomonas aeruginosa MTCC 741 and Klebsiella pneumoniae MTCC 109 in the concentrations of 8AU/ml, 16AU/ml, 32AU/ml, 64AU/ml, 256AU/ml and 512AU/ml, respectively. From the overall observation, this study explored a novel bacteriocin purified from a probiotic bacterium represented potential antimicrobial activities against many human pathogens which suggesting its possible use for the safe therapeutic applications.