PROPERTIES OF DURANCIN GL, A NEW ANTILISTERIAL BACTERIOCIN PRODUCED BY ENTEROCOCCUS DURANS 41D

The properties of the antilisterial durancin GL were characterized. The bacteriocin was the product of Enterococcus durans 41D, which was isolated from Hispanic-style cheese samples. The antibacterial activity of durancin GL was only evident against gram-positive bacteria, including Listeria species. Bacteriocin's activity was retained after treatment with surfactants of different groups (Tween, Brij and sodium dodecyl sulfate), and reducing (beta-mercaptoethanol) or chelating (ethylenediaminetetraacetic acid) agents failed to inactivate the bacteriocin. Durancin GL was active over the pH range of 2-11 and heat resistant for at least 30 min at 100C. However, exposure to 121C for 17 min completely inactivated the bacteriocin. Durancin GL displayed primary metabolite kinetics with the bacteriocin production rate being parallel with the growth cycle of E. durans 41D. The estimated molecular mass of durancin GL was <6 kDa, and it displayed a bactericidal effect on sensitive strains without concomitant cell lysis. The apparently new antilisterial bacteriocin from the putative probiotic strain E. durans 41D may be used to protect food products against various gram-positive bacteria, including the food-borne pathogen Listeria monocytogenes.