Characteristics of bacteriocin-like inhibitory substances from dochi-isolated Enterococcus faecium D081821 and D081833

AIMS: To characterize bacteriocin-like inhibitory substances (BLIS) from two dochi-isolated Enterococcus faecium. METHODS AND RESULTS: Enterococcus faecium D081821 and D081833 were isolated from dochi (a traditional fermented food in Taiwan) and found to produce BLIS with inhibitory activities against Listeria monocytogenes, Clostridium perfringens, and Bacillus cereus. Strains D081821 and D081833 showed different growth temperatures and their BLIS showed different sensitivities to heat, proteolytic enzymes, and antibacterial spectra. Both BLIS were collected, partially purified, and analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE showed that both partially purified BLIS were approximately 3.0 kDa in size. CONCLUSIONS: These results indicate that E. faecium D081821 and D081833 produce different BLIS with strong antibacterial actions against the tested pathogenic bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study suggest that two different BLIS from dochi-isolated lactic acid bacteria have potential for use as food preservatives.