Partial Purification and Characterization of the Mode of Action of Enterocin S37: A Bacteriocin Produced byEnterococcus faecalisS37 Isolated from Poultry Feces

Abstract

The aim of this research was to purify and characterize the mode of action of enterocin S37, a bacteriocin produced byEnterococcus faecalisS37, a strain recently isolated from the chicken feces. Enterocin S37 has a molecular weight comprised between 4 and 5 kDa. It remained active after 1 h at and at pH values ranging from 4.0 to 9.0. Furthermore, cell-free supernatant ofEnterococcus faecalisS37 and purified enterocin S37 were active against Gram-positive bacteria includingListeria monocytogenesEGDe,L. innocuaF,Enterococcus faecalisJH2-2, andLactobacillus brevisF145. The purification of enterocin S37 was performed by ammonium sulfate precipitation followed up by hydrophobic-interaction chromatography procedures. Treatment of enterocin S37 with proteinase K, -chymotrypsin, and papain confirmed its proteinaceous nature, while its treatment with lysozyme and lipase resulted in no alteration of activity. Enterocin S37 is hydrophobic, anti-Listeriaand likely acting by depletion of intracellular K+ions upon action on channels. This study contributed to gain more insights into the mode of action of enterocins.