Mode of action of a novel anti-Listeria bacteriocin (CAMT2) produced by Bacillus amyloliquefaciens ZJHD3-06 from Epinephelus areolatus

Abstract

Bacteriocin CAMT2, produced by Bacillus amyloliquefaciens ZJHD3-06, has been shown to exhibit protective activity against important food spoilage and food-borne bacterial pathogens. This study was conducted to investigate the mode of action of bacteriocin CAMT2 against highly pathogenic Listeria monocytogenes ATCC 19111. The addition of bacteriocin CAMT2 at 64 AU/ml inhibited L. monocytogenes ATCC 19111. An efflux of K + ions, lactic acid dehydrogenase and an increase in extracellular electrical conductivity was observed in CAMT2-treated L. monocytogenes. Electron microscopy showed morphological alterations such as uneven cell surface, accumulation of cell debris and bacterial lysis. These results show that bacteriocin CAMT2 inhibit L. monocytogenes by increasing cell permeability and inducing membrane damage, hence it has the great application potentials in ensuring food safety.