Isolation and characterization of two bacteriocins of Lactobacillus acidophilus LF221.
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.
Bogovic-Matijasić
B
B
Biotechnical Faculty, Zootechnical Department, Domzale, Slovenia. Bojana.Bogovic@bfro.uni-lj.si
Rogelj
I
I
Nes
I F
IF
Holo
H
H
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
D001430:Bacteriocins