Inactivation and injury of Escherichia coli O157 : H7 and Staphylococcus aureus by pulsed electric fields

DAMAR S., Bozoglu F., Hizal M., Bayindirli A.

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY, vol.18, no.1, pp.1-6, 2002 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 18 Issue: 1
  • Publication Date: 2002
  • Doi Number: 10.1023/a:1013900222139
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1-6
  • Keywords: electric field strength, E. coli O157 : H7, inactivation, injury, modelling, pathogens, pulse number, pulsed electric field, S. aureus, HIGH HYDROSTATIC-PRESSURE, CELL-MEMBRANES, SACCHAROMYCES-CEREVISIAE, YEAST-CELLS, MICROORGANISMS, ELECTROPORATION, PASTEURIZATION, TEMPERATURE, FOODS, MILK
  • Middle East Technical University Affiliated: Yes


Two pathogenic microorganisms Escherichia coli O157:H7 and Staphylococcus aureus, suspended in peptone solution (0.1% w/v) were treated with 12, 14, 16 and 20 kV/cm electric field strengths with different pulse numbers up to 60 pulses. Pulsed electric field (PEF) treatment at 20 kV/cm with 60 pulses provided nearly 2 log reduction in viable cell counts of E. coli O157:H7 and S. aureus. S. aureus cells were slightly more resistant than E.coli O157:H7 cells. The results related to the effect of initial cell concentration of E. coli O157:H7 on the PEF inactivation showed that more inactivation was obtained by decreasing initial cell concentration. Any possible injury by PEF was also investigated after applying 20 kV/cm electric field to the microorganisms. As a result, it was determined that there was 35.92 to 43.36% injury in E. coli O157:H7 cells, and 17.26 to 30.86% injury in S. aureus cells depending on pulse number. The inactivation results were also described by a kinetic model.