Effects of high field DC pulses on the viability of Lactobacillus brevis

Inactivation of Lactobacillus brevis cells in suspensions of phosphate buffer solutions of different conductivities (170 mu S/cm to 2230 mu S/cm) using electric pulse application has been investigated. Survivability as a function of pulse application number has shown a logarithmic death for all test conditions. A maximum reduction in survivability was obtained in low-conductivity liquid medium. The pulse energy influences the survival rate of L. brevis cells by altering the liquid temperature during pulse discharge; however, the direct lethal effect of heating was insignificant as the maximum temperature rise was only 22 degrees C upon application of 600 pulses of 8 W-s/pulse.<>