PARTIAL PURIFICATION OF ANTIMICROBIAL PEPTIDES ACTIVE AGAINST FOODBORNE PATHOGENS

LANZA, L; NAVARRO, S.A; BELLOMIO, A; CHALON, M.C.

Buenos Aires

Congreso; Reunion Conjunta de Sociedades de Biociencias; 2017

Bacteriocins are small, ribosomally synthesized antimicrobial peptides that kill bacteria closely related to the producer strain. Hybrid bacteriocins were made by the fusion of genes encoding Enterocin CRL35 (munA), Pediocin PA-1 (pedA) and Microcin V (cvaC) separated by a hinge region. These bacteriocins were constructed in order to obtain peptides with broad antimicrobial spectrum. The aim of this work was to purified different hybrid bacteriocins and microcins available in our laboratory. Microcin E492, Microcin V and Microcin H47 were obtained from supernatants of the producer strains. Hybrid bacteriocins with different hinge regions (Ent35-GGG-Mccv, PedA-GGG-MccV, PedA-GIG-MccV) were purified by disruption of the producing strains and subsequent precipitation of the proteins with 40-50% (NH4)2SO4. The cellular extracts were loaded onto a C18 chromatography cartridge, eluted with acetonitrile and then were concentrated. The antimicrobial peptides were found to be active against different food borne pathogens such as Listeria monocytogenes, Escherichia coli O: 157, Salmonella enterica serovar pullorum and gallinarum. Serial double dilutions of the partially purify peptides were performed. Antibiotic activity units (AU/ml) were calculated as the reciprocal of the highest dilution showing growth inhibition halo against E. coli MC4100. The antimicrobial peptides have potential biotechnological applications as food biopreservative and in the pharmaceutical industry.