title: Purification and characterization of a bacteriocin produced by Lactobacillus acidophilus IBB 801.
abstract: Lactobacillus acidophilus IBB 801 produces a small bacteriocin, designated acidophilin 801, with an estimated molecular mass of less than 6.5 kDa. It displays a narrow inhibitory spectrum (only related lactobacilli but including the Gram-negative pathogenic bacteria Escherichia coli Row and Salmonella panama 1467) with a bactericidal activity. The antimicrobial activity of cell-free culture supernatant fluid was insensitive to catalase but sensitive to proteolytic enzymes such as trypsin, proteinase K and pronase, heat-stable (30 min at 121 degrees C), and maintained in a wide pH range. The proteinaceous compound was isolated from cell-free culture supernatant fluid and purified. Crude bacteriocin was isolated as a floating pellicle after ammonium sulphate precipitation (40% saturation) and partially purified by extraction/precipitation with chloroform/methanol (2/1, v/v). Further purification to homogeneity was performed by reversed phase Fast Performance Liquid Chromatography. The amino acid composition was determined. Amino acid sequencing revealed that the N-terminal end was blocked.
authors.affiliation: Genetic Engineering Laboratory, Institute of Biology, Bucharest, Romania.
authors.forename: M
authors.initials: M
authors.lastname: Zamfir
authors.forename: R
authors.initials: R
authors.lastname: Callewaert
authors.forename: P C
authors.initials: PC
authors.lastname: Cornea
authors.forename: L
authors.initials: L
authors.lastname: Savu
authors.forename: I
authors.initials: I
authors.lastname: Vatafu
authors.forename: L
authors.initials: L
authors.lastname: De Vuyst
mesh_terms: D001430:Bacteriocins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D020128:Inhibitory Concentration 50; D007779:Lactobacillus acidophilus / Q000737:chemistry* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D010434:Pepsin A / Q000494:pharmacology; D012475:Salmonella / Q000187:drug effects; D014357:Trypsin / Q000494:pharmacology
chemical_list: D001430:Bacteriocins; C405711:acidophilin 801; D014357:Trypsin; D010434:Pepsin A