Characteristics of cellular membranes at rehydration of dehydrated yeast Saccharomyces cerevisiae

This paper describes the characteristics of the structural and functional organization of cellular membranes rehydrated after dehydration of the yeast Saccharomyces cerevisiae. It was noted that dehydration and subsequent rehydration of yeast cells causes a considerable increase of cytoplasmic membrane permeability. Addition of CaCl₂, glucose and polyethyleneglycol to the rehydration medium caused a decrease in cell permeability, assessed as the losses of potassium ions, nucleotides, as well as the total losses of intracellular compounds. KCl had a positive effect only at concentrations above 10%. Yeast cells, dried to residual moisture lower than 20%, showed a decrease in membrane permeability as temperatures of the rehydration medium increased up to 38°-43°C. Upon reactivation of viable dehydrated cells in a nutrient medium, a reparation of the structural damages of various intracellular membranes takes place. It was established that at cell dehydration to residual moistures of 8%-12% all the free and a part of bound water is evaporated from cells.