Potential applicability of chymotrypsin-susceptible microcin J25 derivatives to food preservation

Microcin J25 (MccJ25) is a 21-residue ribosomally synthesized lariat peptide antibiotic. MccJ25 is active against such food-borne disease-causing pathogens as Salmonella spp., Shigella spp., and Escherichia coli, including E. coli O157:H7 and non-O157 strains. MccJ25 is highly resistant to digestion by proteolytic enzymes present in the stomach and intestinal contents. MccJ25 would therefore remain active in the gastrointestinal tract, affecting normal intestinal microbiota, and this limits the potential use of MccJ25 as a food preservative. In the present paper, we describe a chymotrypsin-susceptible MccJ25 derivative with a mutation of Gly12 to Tyr that retained almost full antibiotic activity and efficiently inhibited the growth of pathogenic Salmonella enterica serovar Newport and Escherichia coli O157:H7 in skim milk and egg yolk. However, unlike the wild-type MccJ25, the MccJ25(G12Y) variant was inactivated by digestive enzymes both in vitro and in vivo. To our knowledge, our results represent the first example of a rational modification of a microcin aimed at increasing its potential use in food preservation. Copyright © 2009, American Society for Microbiology. All Rights Reserved.Fil: Pomares, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Salomon, Raul Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Pavlova, Olga. State University of New Jersey; Estados UnidosFil: Severinov, Konstantin. State University of New Jersey; Estados Unidos. Russian Academy of Science; RusiaFil: Farias, Ricardo Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Vincent, Paula Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentin