Mechanism of action of pulsed high electric field (PHEF) on the membranes of food-poisoning bacteria is an 'all-or-nothing' effect.
Salmonella typhimurium (CRA 1005) was more sensitive than Listeria monocytogenes (NCTC 11994) to pulsed high electric field (PHEF) treatment in distilled water (10, 15 and 20 kV/cm), 10 mM tris-maleate buffer pH 7.4 (15 kV/cm) and model beef broth (0.75% w/v: 15 kV/cm). Sublethal injury could not be detected using a selective medium plating technique, indicating that bacterial inactivation by PHEF may be an 'all-or-nothing' event. PHEF-induced membrane permeabilization resulted in increased UV-leakage and a decreased ability of L. monocytogenes to maintain a pH gradient.
Russell
N J
NJ
Department of Biological Sciences, Wye College, University of London, Ashford, Kent, UK.
Colley
M
M
Simpson
R K
RK
Trivett
A J
AJ
Evans
R I
RI
D002462:Cell Membrane; D015169:Colony Count, Microbial; D004560:Electricity; D005511:Food Handling; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000254:growth & development*; D012486:Salmonella typhimurium / Q000254:growth & development*