The effects of physical and chemical sublethal treatments on the antibacterial activity of enterocin KP produced by Enterococcus faecalis KP against Escherichia coli O157:H7 and Salmonella Typhimurium were investigated. | Turkish Journal of Biology Turk J Biol (2014) 38: 412-419 © TÜBİTAK doi: Research Article Inhibitory effect of enterocin KP in combination with sublethal factors on Escherichia coli O157:H7 or Salmonella Typhimurium in BHI broth and UHT milk 1, 1 1 2 2 Zeliha YILDIRIM *, Yaselin İLK , Metin YILDIRIM , Kader TOKATLI , Nilgün ÖNCÜL 1 Department of Food Engineering, Faculty of Engineering, Niğde University, Niğde, Turkey 2 Department of Food Engineering, Gaziosmanpaşa University, Tokat, Turkey Received: Accepted: Published Online: Printed: Abstract: The effects of physical and chemical sublethal treatments on the antibacterial activity of enterocin KP produced by Enterococcus faecalis KP against Escherichia coli O157:H7 and Salmonella Typhimurium were investigated. Enterocin KP was not active against intact cells of E. coli O157:H7 or S. Typhimurium. However, the use of enterocin KP together with ethylenediaminetetraacetic acid (50 mM), sodium tripolyphosphate (50 mM), sublethal heating (60 °C for 10 min), cold shock (–20 °C for 2 h), or acid stress (mixture of 40% lactic acid, 16% propionic acid, 16% acetic acid) in BHI medium decreased the cell number of E. coli O157:H7 by , , , , log and S. Typhimurium by , , , , log cfu/mL, respectively. The combination of enterocin KP with ethylenediaminetetraacetic acid decreased the cell number of E. coli O157:H7 in UHT milk to undetectable level, enterocin KP plus sodium tripolyphosphate or enterocin KP plus sublethal heating caused a reduction by and log cycles. The results of this study showed that enterocin KP could be applied as a biopreservative to inhibit E. coli O157:H7 and S. Typhimurium in combination with physical and food grade chemical hurdles. Key words: Bacteriocin, enterocin KP, sublethal injury, gram-negative bacteria, UHT milk 1. .
