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 7.27, 6.28, 3.39, 3.06, 4.20 log and S. Typhimurium by 7.21, 6.20, 3.64, 3.38, 3.98 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 6.07 and 5.68 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.
Bacteriocin, enterocin KP, sublethal injury, gram-negative bacteria, UHT milk
YILDIRIM, ZELİHA; İLK, YASELİN; YILDIRIM, METİN; TOKATLI, KADER; and ÖNCÜL, NİLGÜN
"Inhibitory effect of enterocin KP in combination with sublethal factors on Escherichia coli O157:H7 or Salmonella Typhimurium in BHI broth and UHT milk,"
Turkish Journal of Biology: Vol. 38:
3, Article 13.
Available at: https://journals.tubitak.gov.tr/biology/vol38/iss3/13