Abstract
Enterococcus faecium WHE 81, isolated from a smear-surface soft cheese, was shown to produce at least two bacteriocins, with high anti-Listeria activity. One of the bacteriocins produced was purified to homogeneity by ammonium sulfate precipitation, desalting on an ODP-90 reversephasecolumn, SP Sepharose HP cation exchange chromatography and C22/C18 reverse-phase chromatography. This purification method is superior to the previously published method, resulting in a 2,500-fold increase in the specific activity, and a recovery of 46%. Mass determination and sequencing of this bacteriocin revealed a peptide of 53 amino acid residues with a molecular mass of 5,462.2 Da. Two cysteine residues (positions 23 and 52) form a disulfide bond. The identified peptide is a class II bacteriocin whose sequence is similar to that of enterocin B produced by Enterococcus faecium CTC492, a strain isolated from Spanish dry fermented sausages.
