| Abstract [eng] |
In my dissertation, I focused on answering questions needed for successful knowledge transfer from fundamental yeast electroporation research to biotechnological applications. It was shown that without control, the shape of a pulse depends on conductivity, which can increase effective pulse duration by up to 50 % and decrease yeast cells' viability by up to 10 %. Irreversible damage after exposure to PEF was detected in the plasma membrane, but not in a cell wall, while both structures' integrity stabilized within 100 seconds. For the very first-time yeast-modified electrodes were successfully used to investigate electroporation of the same cells. Exposure to PEF resulted in lower redox activity, which could be compensated entirely by adjusting the extracellular concentration of NADH to 1 mM. Our study shows the applicability of PEF technology for the modulation of amperometric signals. To our best knowledge, this study is the first to show that exposure of yeast cells to electric field pulses with nanosecond duration causes expression of features characteristic to caspase-dependent death. Exposure to PEF was followed by the activation of yeast metacaspases, permeabilization of the plasma membrane, and externalization of phosphatidylserine. Lastly, we showed that pulses with nanosecond duration could selectively inactivate yeast cells while keeping beneficial bacteria alive. |
