Numerical analysis of impedance spectra of yeast suspensions

Abstract

Analysis of impedance spectrum of electroporated biological cell suspensions allows evaluating the state of permeabilization produced by the applied electric field. In this article we used a genetic algorithm to determine parameters of a proposed model for the impedance of suspension adjusting them numerically in order to minimize the error in relation to experimental spectra of Kluyveromyces marxianus CBS 6556 yeasts suspended in distilled water. It was possible to determine the variation of conductivity of suspension avoiding the influence of electrode polarization and dielectric dispersion due to interfacial and diffusion polarization on the cell surface. It was observed that the conductivity in the range of 1 to 100 KHz increases 2.5 times with pulses of 400 KV/m.

Assessment of the electrochemical effects of pulsed electric fields in a biological cell suspension

“…There was thus interference of the electrochemical phenomena during current measurements. A similar observation was already made by Ramos et al [14]. Since the cell interior is released to the medium, new interfaces are created, on the one hand by the closest cells to the electrodes and, on the other, between cells that are originally subject to an inhomogeneous local electric field.…”

“…New insight was obtained into the kinetics of diffusion due to the creation of new interfaces at low frequency, which leads to a current path increase, i.e., decreased conductivity even with the presence of membrane pores. M A N U S C R I P T 13 1,209×10 13 4,643×10 13 3,155×10 14 7,736×10 13 A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 28 Highlights -An experimental protocol was designed to elucidate pulsed electric field effects on the electrode/electrolyte interface. -An electric field affects electrodes and the degree of alteration depends on the electrolyte conductivity.…”

“…Electrode/electrolyte interface impedance has strong dispersion of resistance and reactance at low frequencies. Ion diffusion within a double layer of cells also results in low frequency dielectric dispersion [13,14]. On the other hand, when a high-voltage electric pulse is applied to an electrolyte solution, a variety of electrolysis reactions occur at the electrode-solution interfaces in addition to cell membrane permeabilization [15].…”