title: Biochemical, antimicrobial and molecular characterization of a noncytotoxic bacteriocin produced by Lactobacillus plantarum ST71KS.
abstract: Lactobacillus (Lb.) plantarum ST71KS was isolated from homemade goat feta cheese and identified using biochemical and molecular biology techniques. As shown by Tricine-SDS-PAGE, this lactic acid bacterium produces a bacteriocin (ST71KS) with an estimated molecular weight of 5.0 kDa. Bacteriocin ST71KS was not affected by the presence of α-amylase, catalase and remained stable in a wide range of pH and after treatment with Triton X-100, Triton X-114, Tween 20, Tween 80, NaCl, SDS, urea and EDTA. This bacteriocin also remained active after being heated at 100 °C for 2 h and even after 20 min at 121 °C; however, it was inactivated by proteolitic enzymes. Production of bacteriocin ST71KS reached 6400 AU/mL during stationary growth phase of Lb. plantarum cultivated in MRS at 30 °C and 37 °C. Bacteriocin ST71KS displayed a bactericidal effect against Listeria monocytogenes strains 603 and 607 and did not adsorb to the producer cells. Lb. plantarum ST71KS harbors two bacteriocin genes with homology to plantaricin S and pediocin PA-1. These characteristics indicate that bacteriocin ST71KS is a class IIa bacteriocin. The peptide presented no toxic effect when tested in vitro with kidney Vero cells, indicating safe technological application to control L. monocytogenes in foods.
authors.affiliation: Laboratory of Food Microbiology, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes 580, Bloco 14, 05508-000 São Paulo, SP, Brazil. rafacrmartinez@yahoo.com.br
authors.forename: Rafael Chacon Ruiz
authors.initials: RC
authors.lastname: Martinez
authors.forename: Monica
authors.initials: M
authors.lastname: Wachsman
authors.forename: Nicolas Ignacio
authors.initials: NI
authors.lastname: Torres
authors.forename: Jean Guy
authors.initials: JG
authors.lastname: LeBlanc
authors.forename: Svetoslav Dimitrov
authors.initials: SD
authors.lastname: Todorov
authors.forename: Bernadette Dora Gombossy de Melo
authors.initials: BD
authors.lastname: Franco
mesh_terms: D000818:Animals; D001430:Bacteriocins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D002460:Cell Line; D002611:Cheese / Q000382:microbiology*; D002522:Chlorocebus aethiops; D006801:Humans; D006863:Hydrogen-Ion Concentration; D048191:Lactiplantibacillus plantarum / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014709:Vero Cells
chemical_list: D001430:Bacteriocins