Purification of Bacteriocin from Lactobacillus plantarum KY449289 and its Role in the Preservation of Mixed Fruit Juice

Abstract

Background:: The aim of this study is to isolate, extract and purify the antibacterial protein from Lactobacillus plantarum KY449289 and to assess its bio preservative potential. Objective:: The present study was conducted to evaluate the laxative activity of Hydroethanolic Pericarp Extract of sapindus emarginatus (HESE) in animal models. Methods:: Bacteriocins are antimicrobial peptides synthesized ribosomally which can be used as bio-preservative reducing the risk of chemical preservative’s effect and also replacing the thermal treatments. This study aims to isolate, purify the antibacterial protein from Lactobacillus plantarum KY449289 and to assess its bio preservative potential. In this study, twenty strains were isolated from a yogurt sample and preliminary characterization was carried out, such as morphological, biochemical, and molecular levels as a preliminary assay. Results:: The characterized strains were assessed for the antibacterial activity by well diffusion assay, whereas all twenty strains were shown to have a antibacterial activity against foodborne pathogens, among which two strains VITMM04 and VITMM05 shows the highest zone of inhibition of 15 mm and 10 mm respectively against Listeria monocytogenes. The potent isolate VITMM05 solely showed a broad spectrum antibacterial activity against the pathogens. These strains were further subjected to optimization, purification, and application studies. A high increase in the inhibition zone was recorded with an optimum temperature of 35°C and its activity was found to be stable up to 85°C, optimum pH 6, and 5 mM of EDTA as an enhancer surfactant. On subjected to RP-HPLC, the purified sample showed a distinct peak at 2.192 min corresponding to the peak at 2.192 min for standard bacteriocin. Conclusion:: The six-fold purified bacteriocin was effective in controlling 87% of the microbial population with 20mm zone of inhibiton against the Listeria monocytogenes and this shows the effective role of purified bacteriocin in inhibiting bacterial growth in a greater extent.