Effect of Hydrostatic Pressure and Electroporation on Bactericidal Efficiency in Combination with Bacteriocins and Lysozyme. Phase I.
Final rept. Oct 93-Sep 94,
WYOMING UNIV LARAMIE
Pagination or Media Count:
The bactericidal efficiency of ultrahigh hydrostatic pressure UMP and pulsed electric field PEF were studied in combination with two acteriocins, nisin A and pediocin AcH, and lysozyme. Several Gram-positive and Gram-negative bacterial species and strains associated with food spoilage and foodborne diseases were tested. The results showed that both UHP and PEF inflict lethal and sublethal injury to Gram-positive and Gram-negative bacterial cells. As the sublethally-injured cells became sensitive to the bactericidal action of the two bacteriocins and lysozyme, the combination of the UHP and PEF treatment, along with bacteriocin and lysozyme resulted in greater viability loss than when only the UHP or PEF are used. In general, under the study conditions, UHP and bacteriocins produced more viability loss than PEF with and without bacteriocins. By combining bacteriocins and lysozyme, UHP at 30,000 psi for 1 min produced viability loss of 13.8 logs in Listeria monocytogenes Scott A and 6.3 logs in Salmonella typhimurium as compared to 2.8 logs for both species by UHP alone and 4.7 and 4.1 logs, respectively, by UHP bacteriocins.
- Medicine and Medical Research