Antimicrobial, cytotoxic effect and purification of bacteriocin from vancomycin susceptible Enterococcus faecalis and its safety evaluation for probiotization

- RP-HPLC C-18 column purified bacteriocin CV7 found to be 4.829 kDa by Tricine-SDS PAGE and MALDI-TOF MS.
- Bacteriocin CV7 inhibits important food borne pathogens including L. monocytogenes and Salmonella.
- Cytotoxicity of bacteriocin CV7 by MTT assay showed lower survival inhibition on HeLa than HT-29 cell line.
- Strain E. faecalis CV7 does not harbor virulence genes esp, ace, cylB, cylA and efaAfs but contains asa1.

A vancomycin susceptible Enterococus faecalis CV7 produced bacteriocin was purified by size exclusion chromatography followed by RP-HPLC C-18 column. Tricine-SDS PAGE unrevealed molecular mass was further confirmed by MALDI-TOF MS as 4.829 kDa. This bacteriocin showed broad spectrum of anti-bacterial activity against important food borne pathogens mainly against Salmonella typhi and this activity also found to be withstood after treatment with different proteolytic enzymes, temperature, pH, solvents and detergents. Cytotoxicity of bacteriocin CV7 by MTT assay showed that lower survival inhibition on HeLa than HT-29 cell line at lower concentrations conclude its potentiality in food biopreservation. Results obtained from PCR amplifications revealed that strain E. faecalis CV7 does not harbor virulence genes esp, ace, cylB, cylA and efaAfs but contains asa1. With this, surviving in the presence of low pH and bile oxgall promising its safety as probiont to control Salmonella infections.