Characterization of a novel circular bacteriocin from 1-3, and its mode of action against .

In this study, isolate 1-3 was selected out for its anti- Listeria potency, from which a novel circular bacteriocin, velezin, was purified out of the fermentate, and then characterized. Facilitated with a broad antibacterial spectrum, velezin has demonstrated decent inhibitive activity against of foodborne pathogen ATCC 19115. It exerted the antibacterial activity through damaging the membrane integrity of targeted cell and causing leakage of vital elements, including K ion. It was noteworthy that velezin also inhibited the biofilm formation by ATCC 19115. At the challenge of velezin, ATCC 19115 up-regulated expression of genes associated with membrane, ion transporters, stressing-related proteins as well as the genes responsible for the synthesis of small molecule. Taken together, velezin may have potential to be a candidate as natural additive used in food/feed in the future.