Yeast survival during thermal and osmotic shocks is related to membrane phase change.
The aim of this work was to study the survival of yeast cells exposed to a combination of thermal and osmotic treatments, as occurs during drying processes, and assess associated changes in fluidity of the plasma membrane, which have been studied previously in this laboratory. Cells that were maintained at a nonlethal dehydration temperature (5 or 30 degrees C) were rapidly dehydrated up to 120 MPa, and then thermal stress was suddenly applied between 5 and 30 degrees C. Cell viability was measured after a return to initial conditions (i.e., 1.38 MPa and 25 degrees C). Results showed that the viability of yeast cells exposed to identical combined thermal and osmotic treatments was dependent on the chronology of the stress application. Finally, the temperature at which the dehydration was conducted, up to 120 MPa, appeared to be the main factor involved in cell survival and could be related to fluidity variations of the plasma membrane.
Guyot
Stéphane
S
Laboratoire de Génie des Procédés Alimentaires et Biotechnologiques, Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et à l'Alimentation, 1 Esplanade Erasme, 21000 Dijon, France.
Ferret
Eric
E
Gervais
Patrick
P
D016880:Anisotropy; D002462:Cell Membrane; D002470:Cell Survival; D009997:Osmotic Pressure; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism; D013696:Temperature; D014867:Water / Q000378:metabolism
D014867:Water