The link between yeast cell wall porosity and plasma membrane permeability after PEF treatment

Abstract

An investigation of the yeast cell resealing process was performed by studying the absorption of the tetraphenylphosphonium (TPP+) ion by the yeast Saccharomyces cerevisiae. It was shown that the main barrier for the uptake of such TPP+ ions is the cell wall. An increased rate of TPP+ absorption after treatment of such cells with a pulsed electric field (PEF) was observed only in intact cells, but not in spheroplasts. The investigation of the uptake of TPP+ in PEF treated cells exposed to TPP+ for different time intervals also showed the dependence of the absorption rate on the PEF strength. The modelling of the TPP+ uptake recovery has also shown that the characteristic decay time of the non-equilibrium (PEF induced) pores was approximately a few tens of seconds and this did not depend on the PEF strength. A further investigation of such cell membrane recovery process using a florescent SYTOX Green nucleic acid stain dye also showed that such membrane resealing takes place over a time that is like that occurring in the cell wall. It was thus concluded that the similar characteristic lifetimes of the non-equilibrium pores in the cell wall and membrane after exposure to PEF indicate a strong coupling between these parts of the cell.

Yeast Cells in Microencapsulation. General Features and Controlling Factors of the Encapsulation Process

“…Pressure, vacuum, and electric fields. To our knowledge, to date, only a handful of reports have used high pressures for encapsulation, which may be beneficial due to the induction of pores in the cell wall, as has been shown for shear forces or short pulsed electric field (PEF) [ 136 ]. However, there appears to be no conclusive evidence of improvements in encapsulation efficiency through the application of high pressure: Shi et al used high pressures (25 MPa, 40 °C, 4 h) for chlorogenic acid [ 27 ] or resveratrol [ 29 ]), but no control at room pressure was employed; Errenst et al employed a high pressure system where a limonene/water emulsion in CO 2 was mixed with yeast carried by a nitrogen stream [ 94 ], but there the high pressure was an integral component of their process (=no control at low pressure would be possible).…”

Electroporation Assisted Improvement of Freezing Tolerance in Yeast Cells

“…Such pulses are likely to increase the permeability of plasma membrane with a minor impact on the viability. Some lethal effects of pulsed electric field on yeast cells, like irreversible permeabilization or activation of metacaspases, were investigated and discussed previously [ 17 , 18 , 19 , 20 ].…”

Compact Square-Wave Pulse Electroporator with Controlled Electroporation Efficiency and Cell Viability

“…It was evaluated by employing membrane-impermeable fluorescent dyes intercalated into nucleic acids. Greater amounts of intracellular dye resulted in greater fluorescence intensity (FI), corresponding to the increased permeability [36]. It was found that both pulses (the electric field strength was 26 kV/cm) generated with and without the crowbar circuit induced electroporation.…”