title: Isolation and characterization of two bacteriocins of Lactobacillus acidophilus LF221.
abstract: Lactobacillus acidophilus LF221 produced bacteriocin-like activity against different bacteria including some pathogenic and food-spoilage species. Besides some lactic acid bacteria, the following species were inhibited: Bacillus cereus, Clostridium sp., Listeria innocua, Staphylococcus aureus, Streptococcus D. L. acidophilus LF221 produced at least two bacteriocins, acidocin LF221 A and acidocin LF221 B, which were purified by ammonium sulphate precipitation, ion-exchange chromatography, hydrophobic interaction and reverse-phase FPLC. The antibacterial substances were heat-stable, sensitive to proteolytic enzymes (trypsin, pepsin, pronase, proteinase K) and migrated as 3500- to 5000-Da proteins on sodium dodecyl sulphate/polyacrylamide gel electrophoresis. The sequences of 46 amino-terminal amino acid residues of peptide A and 35 of peptide B were determined. Among the residues identified, no modified amino acids were found. No significant homology was found between the amino acid sequences of acidocin LF221 A and other bacteriocins of lactic acid bacteria and 26% homology was found between acidocin LF221 B and brevicin 27. L. acidophilus LF221 may be of interest as a probiotic strain because of its human origin and inhibition of pathogenic bacteria, especially clostridium difficile.
authors.affiliation: Biotechnical Faculty, Zootechnical Department, Domzale, Slovenia. Bojana.Bogovic@bfro.uni-lj.si
authors.forename: B
authors.initials: B
authors.lastname: Bogovic-Matijasić
authors.forename: I
authors.initials: I
authors.lastname: Rogelj
authors.forename: I F
authors.initials: IF
authors.lastname: Nes
authors.forename: H
authors.initials: H
authors.lastname: Holo
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002850:Chromatography, Gel; D006863:Hydrogen-Ion Concentration; D007779:Lactobacillus acidophilus / Q000737:chemistry*; D008969:Molecular Sequence Data; D008970:Molecular Weight
chemical_list: D001430:Bacteriocins