Find in Library

LF221 strain is a Lactobacillus isolate from a baby’s faeces that was previously found to produce bacteriocin(s) with inhibitory activity against a wide range of bacterial species including some pathogenic and food-spoilage (Bacillus cereus, Clostridium sp., Listeria innocua, Staphylococcus aureus). Isoelectric point and molecular mass of bacteriocin complex and subunits were estimated. Precipitation with ammonium sulphate, cation exchange chromatography, C8 hydrophobic interaction chromatography and reverse-phase FPLC chromatography were used to isolate bacteriocins from the supernatant of MRS culture. Amino acid composition and partial N-terminal amino acid sequences of two isolated bacteriocins were determined. Bacteriocins were present in MRS supernatant as aggregates with Mw>150.000 and pI 5.1-5.3, while Mw of subunits was 3500-5000. A high content of glycin and alanin was observed for both bacteriocins. The N-terminal amino acid sequences showed little similarity with those of other bacteriocins. Acidocins LF221 A and B appear to belong to the II class of LAB bacteriocins.