THE EFFECT OF AN ABRUPT STEPWISE REDUCTION IN PRESSURE ON THE INTEGRITY OF THE EUKARYOTIC AND PROKARYOTIC CELL-ENVELOPE

The influence of an abrupt pressure variation on cell integrity was studied in the case of Saccharomyces cerevisiae, Escherichia coli, and chinese hamster ovarian and tobacco cells. Experiments were carried out with a new design of normal stress generator operating without any gas. The cells were immersed in a liquid phase to avoid any shear stress. The influence of the cell physiologic state was studied by harvesting cell suspensions at different batch culture times. No shearing effect or loss of membrane integrity was obtained, whatever cell type was considered; there was no significant difference in cellular protein and enzyme concentration in the extracellular medium, before and after the pressure shock. These results show that the cell envelope's role of barrier to large molecules was not modified by a rapid pressure variation.