Modelling the effect of osmolality on the bursting strength of yeast cells

When yeast cells are resuspended in buffer prior to homogenisation, the dil uent osmotic pressure can have a significant effect on cell mechanical stre ngth. In this paper a model is proposed which describes the relationship be tween the cell bursting force and the osmotic pressure of the diluent, usin g chemical potential and force balance analyses. Yeast cells were exposed f or 1 h to diluents with osmolalities varying from almost 0 to 700 mmol kg(- 1) before their bursting strengths were measured by micromanipulation. The experimental data were compared with the predictions made from the model an d in general they were in good agreement. It is expected that this model mi ght be used to understand cell disruption behaviour in downstream processin g equipment such as homogenisers. (C) 1999 Elsevier Science B.V. All rights reserved.