DIELECTRIC BEHAVIOR OF YEAST CELLS IN SUSPENSION

Abstract

Intact yeast and green algal cells were found to have high apparent dielectric constants of 2, 100 and 400. When a thin layer of low conductivity is assumed to be in the cell envelope, the dielectric behavior of cell suspensions can satisfactorily be interpreted in terms of MAXWELL-WAGNER's mechanism.The thin layer seems to correspond to the plasma membrane, having a membrane capacity of 1μF•cm-2.In analyzing the observed data on the impedance property of yeast cells in suspension, it was found necessary to take into consideration the presence of the cell wall as well as the plasma membrane. However, it was shown to be adequate to regard a cell as a homogeneous particle with a single thin layer of low conductivity located in the cell surface, provided that contributions from the cell wall are dealt with by adopting such a modified definition of volume fraction as to exclude the volume occupied by the cell wall.