Anhydrobiosis: Inside yeast cells

Anhydrobiosis in yeasts: Psychrotolerant yeasts are highly resistant to dehydration

“…Determination of the growth kinetics of these strains revealed that they all grew rather slowly in yeast extract peptone dextrose nutrient medium at 25°C. The midstationary growth phase, when yeast cells are the most resistant to dehydration–rehydration treatment (Rapoport, ; Rapoport et al, ), was reached after approximately 120 hr of growth. All samples for further studies were taken at this point of culture growth.…”

“…They provide a better understanding of the role of water in the maintenance of various cell structures and biological macromolecules and reveal the potential opportunities for living organisms to survive under extreme conditions. Application of this knowledge is important for the traditional production of active (or instant) dry yeast preparations for the food industry, as well as for the nonconventional use of viable dry yeasts (Rapoport, ; Rapoport, Turchetti, & Buzzini, ; Rapoport, Golovina, Gervais, Dupont, & Beney, ). In addition, as yeast cells are an efficient eukaryotic cell model, information on intracellular protective reactions that promote the survival of living organisms under extreme conditions could also be extrapolated for higher organisms, such as in medical applications.…”

Anhydrobiosis in Yeasts: Changes in Mitochondrial Membranes Improve the Resistance of Saccharomyces cerevisiae Cells to Dehydration–Rehydration

“…In some cases, it was reached by a direct decrease in the phase transition temperature of the plasma membrane lipids. This was conducted by using rehydration liquids at high temperatures (above 38-43 • C) or by gradual rehydration of the dry cells as we have carried out here, first using water vapor and then in liquid [7,8,42,45]. Previous studies have also used trehalose, sugars, and polyols as protective compounds that decrease the phase transition temperatures of membrane lipids [13,22,24].…”

“…One large group of organisms that are able to enter the state of anhydrobiosis are yeasts, and it is generally supposed that yeasts are more resistant to the dehydration procedure in comparison to bacterial cells. There are large differences between yeast strains survival during dehydration-rehydration treatments, as well as during their storage in the state of anhydrobiosis [5][6][7][8]. It has been shown that halotolerant, thermoresistant, and psychrophilic yeasts are more resistant to dehydration than the conventional mesophilic baker's yeast Saccharomyces cerevisiae [9][10][11].…”

“…These protective compounds include trehalose, polyols, proline, glutathione, heat shock proteins, and others [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. It was also shown that all intracellular organelles are subject to definite changes during dehydration and rehydration procedures [8]. It appeared that the most resistant organelles are mitochondria, which restore their activities at the early stages of the cell's reactivation process [34].…”