Bacteriocin 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.

A new low molecular weight brevicin produced by Lactobacillus brevis NS01 has greater antimicrobial activity on Gram positive and negative food borne bacteria. This is stable at high temperature acidic to neutral pH, non proteolytic enzymes and organic solvents. The synergistic effect of brevicin with ethylenediaminetetraacetic acid (EDTA), sodium lactate (NaL) and potassium sorbate (KS) showed that better effect is with EDTA. Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) studies showed that the presence of aliphatic C-H stretching of fatty acids and this peptide has vinyl protons and β substituted aliphatic system. Their biopreservative efficacy was also proved using purified brevicin in milk and could control the bacterial growth in milk up to 18 days.

This study demonstrates that the S. typhi strains were attenuated and could be good vaccine candidates in future.

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