Local heating and stresses across membranes of microorganisms stressed with electric field

Pulsed electric field (PEF) may cause irreversible damage to bio-membranes of microorganisms, as electromechanical stresses induced across their membranes can stretch and rupture these phospholipid bi-layers. Local heating is important for further understanding of the biological action of the externally applied electric field as typically the PEF treatment is considered to be a nonthermal process: any increase in the global temperature of the microbial liquid suspension during this process does not result in the thermal inactivation of microorganisms. This paper is aimed at investigation of the transient local heating and transient mechanical stresses across biomembranes of model microorganisms stressed with the external electric field using a model developed in COMSOL Multiphysics. The obtained results demonstrate that high-field impulses can result in the development of strong local electro-mechanical stresses across the membrane, and significant local over-heating of the membrane and the cell wall, as compared with the global temperature of the external suspension. These results and the developed model can help in further understanding the biological action of the impulsive electric fields, and in further development and optimisation of the PEF technology.