Enterocin TW 21, a novel bacteriocin from dochi ‐isolated E nterococcus faecium D 081821

Aims Purification and characterization of a novel bacteriocin produced by strain E nterococcus faecium D 081821. Methods and Results E nterococcus faecium D 081821, isolated from the traditional Taiwanese fermented food dochi (fermented black beans), was previously found to produce a bacteriocin against L isteria monocytogenes and some G ram‐positive bacteria. This bacteriocin, termed enterocin TW 21, was purified from culture supernatant by ammonium sulfate precipitation, S ep‐ P ak C 18 cartridge, ion‐exchange and gel filtration chromatography. Mass spectrometry analysis showed the mass of the peptide to be approximately 5300·6 Da. The N ‐terminal amino acid sequencing yielded a partial sequence NH 2 ‐ ATYYGNGVY x NTQK by Edman degradation, and it contains the consensus class II a bacteriocin motif YGNGV in the N ‐terminal region. The open reading frame ( ORF ) encoding the bacteriocin was identified from the draft genome sequence of E nterococcus faecium D 081821, and sequence analysis of this peptide indicated that enterocin TW 21 is a novel bacteriocin. Conclusions Enterococcus faecium D 081821 produced a bacteriocin named enterocin TW 21, the molecular weight and amino acid sequence both revealed it to be a novel bacteriocin. Significant and Impact of Study A new member of class II a bacteriocin was identified. This bacteriocin shows great inhibitory ability against L .  monocytogenes and could be applied as a natural food preservative.