Osmotic destruction of Saccharomyces cerevisiae is not related to a high water flow rate across the membrane
Résumé
Influence of the kinetics of osmotic pressure variation on yeast viability was related to the rate of water transfer across the yeast membrane. A very high value of membrane hydraulic permeability (Lp>6 × 10−11 m s−1 Pa−1) of the yeast Saccharomyces cerevisiae implies the presence of aqueous pores in the yeast membrane and explains the yeast resistance to a very high osmotic flow. The high water flow rate can not explain, by itself, the cell mortality following an osmotic shock. Experiments performed at different osmotic pressure levels show that the yeast death under osmotic shifts was related to the coupled effects of the kinetics of osmotic pressure variation and of the total osmotic pressure level of the medium.