Physical chemical and biological characterization of a new bacteriocin produced by Bacillus cereus NS02

ObjectiveTo screen the bacteriocinogenic isolate from buffalo milk and to characterize it on physical, chemical and biological aspects for the application in biopreservation.MethodsBacillus cereus (B. cereus) was isolated and assessed for its baceteriocinogenic activity. Bacteriocin was produced and purified by ammonium sulphate precipitation, dialysis and gel filtration chromatography. Purified bacteriocin was used to check its antimicrobial activity against food borne bacteria. Effect and stability of bacteriocin was determined with the respect to temperature, pH, enzymes, organic solvents and chemicals. Bacteriocin was also subjected to SDS PAGE analysis to determine its molecular weight. In addition, functional groups exist in the bacteriocin was determined by FTIR analysis.ResultsB. cereus was identified by 16S rRNA sequence analysis. Bacteriocin showed increased activity against all the bacteria used and its activity unit was found to be 51, 200 AU/mL. It was stable to high temperature (100 °C) and wide range of pH (3-10), sensitive to proteolytic enzymes and resistant to nonproteolytic enzymes. It was low molecular weight (3.5 – 6 KDa) protein and FTIR study revealed the presence of amide group and NH stretching.ConclusionsBacteriocin produced in this study possesses the highest antimicrobial activity against both gram positive and gram negative bacteria thereby it has immense application as biopreservative agent. FTIR proved its peptide nature.