Inhibitory effect of enterocin KP in combination with sublethal factors on Escherichia coli O157:H7 or Salmonella Typhimurium in BHI broth and UHT milk

Authors : Zeliha YILDIRIM, Yaselin İLK, Metin YILDIRIM, Kader TOKATLI, Nilgün ÖNCÜL

Pages : 412-419

Doi:10.3906/biy-1310-69

View : 21 | Download : 11

Publication Date : 2014-12-01

Article Type : Research Paper

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 insert ignore into journalissuearticles values(50 mM);, sodium tripolyphosphate insert ignore into journalissuearticles values(50 mM);, sublethal heating insert ignore into journalissuearticles values(60 °C for 10 min);, cold shock insert ignore into journalissuearticles values(-20 °C for 2 h);, or acid stress insert ignore into journalissuearticles values(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.
Keywords : Key words Bacteriocin, enterocin KP, sublethal injury, gram negative bacteria, UHT milk