Antilisterial Activity of Bacteriocin HY07 from Enterococcus faecium HY07 Isolated from Chinese Sausages

Abstract

In this study, we present a partial purification of bacteriocin HY07 from E. faecium HY07 isolated from Chinese sausage, which exhibited antimicrobial activity to Listeria, Salmonella, Shigella, Staphylococcus, Clostridium, and Bacillus. E. faecium HY07 was shown to lack haemolytic activity and found to be sensitive to tested antibiotics (rifampicin, vancomycin, teicoplanin, and penicillin G). Bacteriocin HY07 was sensitive to proteolytic enzymes, but stable between pH 2.0–10, and heat resistance (15 min at 121°C). In addition, production of bacteriocin HY07 started at the early exponential phase and reached its maximum at the stationary phase, and exerted bacteriostatic effect to Listeria monocytogenes 54002. Bacteriocin HY07 was estimated below 6.5 kDa by tricine-SDS-PAGE. Growth in the presence of tryptone stimulated bacteriocin production. However, lower activity was recorded when the bacteria were grown in the presence of meat extract or yeast extract. MRS broth supplemented with 20 g/L glucose yielded bacteriocin levels of 160 AU/mL, but the production of bacteriocin HY07 was repressed by more than 50% when glucose exceeded 30 g/L. Growth in the presence of maltose, fructose, fructose, sucrose, lactose, and galactose yielded lower activity of bacteriocin. MRS medium supplemented with glycerol repressed bacteriocin production.

Key words:

• E. faecium
• sausage
• bactericoin HY07
• production