DIELECTRIC CHARACTERIZATION OF THE YEAST CELL BUDDING CYCLE

We combine experimental electrorotation data and the numerical analysis of the electrorotation chamber and cell to electrically characterize the Saccharomyces cerevisiae yeast budding cell cycle and to obtain the electrical parameters of the cell. To model the yeast cell we use spherical and doublet-shaped geometries with a four layered structure: cytoplasm, membrane, inner and outer walls. To derive the geometrical and electrical parameters of the yeast model we use the finite element method to calculate the yeast rotational velocity spectrum and apply the least-square method to fit the calculated values to experimental data. We show that the calculated yeast electrorotation spectra undergo significant changes throughout its budding cycle and that the calculated spectra fit experimental data obtained for 0% (start) and 50% representative budding stages very well. The analysis also shows the small variation of the rotation crossover frequency within a full span of the yeast growth cycle. As an application of this work, we apply the Maxwell-Wagner formalism to obtain the dielectric spectra of truly synchronized yeast suspensions.