title: Purification and partial characterization of novel bacteriocin L23 produced by Lactobacillus fermentum L23.
abstract: Lactobacillus fermentum strain L23 produced a small bacteriocin, designated bacteriocin L23, with an estimated molecular mass of < 7000 Da. Isolation, purification, and partial characterization of bacteriocin L23 are described. It displayed a wide inhibitory spectrum including both Gram-negative and Gram-positive pathogenic strains and two species of Candida. The antibacterial activity of cell-free culture supernatant fluid was not affected by catalase or urease but was abolished by the proteolytic enzymes trypsin and protease VI. Bacteriocin L23 was heat stable (60 min at 100 degrees C) and showed inhibitory activity over a wide pH range (4.0 to 7.0). The proteinaceous compound was isolated from cell-free culture supernatant fluid and purified. Crude bacteriocin sample was prepared by a process of ammonium sulfate precipitation, gel filtration, thin-layer chromatography, bioautography, and reversed-phase HPLC.
authors.affiliation: Departamento de Microbiología e Inmunología, Universidad Nacional de Río Cuarto, 5800, Río Cuarto, Córdoba, Argentina.
authors.forename: Liliana M
authors.initials: LM
authors.lastname: Pascual
authors.forename: María B
authors.initials: MB
authors.lastname: Daniele
authors.forename: Walter
authors.initials: W
authors.lastname: Giordano
authors.forename: María C
authors.initials: MC
authors.lastname: Pájaro
authors.forename: Isabel L
authors.initials: IL
authors.lastname: Barberis
mesh_terms: D000645:Ammonium Sulfate; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001430:Bacteriocins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D052197:Limosilactobacillus fermentum / Q000737:chemistry* / Q000302:isolation & purification; D008970:Molecular Weight; D014357:Trypsin / Q000378:metabolism; D014621:Vagina / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001430:Bacteriocins; D014357:Trypsin; D000645:Ammonium Sulfate