To investigate the effects of pulsed electric fields and/or temperature on the viability of the bacterium Mycobacterium paratuberculosis. Furthermore Listeria monocytogenes cells and Bacillus cereus endospores were investigated.
Exposure duration: 25 min
|Chamber||uniform field static chamber|
|Additional info||The test chamber consisted of a disk of 10 mm perspex, with a central hole cut through it to hold a 1.9 ml of sample volume. The brass plates were fitted on both sides of the central hole. The test chamber was immersed in a circulating constant temperature water bath.|
|electric field strength||30 kV/cm||unspecified||unspecified||-||-|
The viability of Mycobacterium paratuberculosis, suspended either in peptone water or sterilized cow's milk, was effectively reduced by pulsed electric fields at 50°C. Whereas a treatment with pulsed electric fields at lower temperatures or heating alone at 50°C and 70°C, respectively, resulted in less lethality. Electon microscopy studies revealed substantial damages at cellular level to M. paratuberculosis caused by pulsed electric fields. Listeria monocytogenes cells and Bacillus cereus endospores were used to validate the test method.