title: Cold osmotic shock in Saccharomyces cerevisiae.
abstract: Saccharomyces cerevisiae NCYC 366 is susceptible to cold osmotic shock. Exponentially growing cells from batch cultures grown in defined medium at 30 C, after being suspended in 0.8 m mannitol containing 10 mm ethylenedia-minetetraacetic acid and then resuspended in ice-cold 0.5 mm MgCl(2), accumulated the nonmetabolizable solutes d-glucosamine-hydrochloride and 2-aminoisobutyrate at slower rates than unshocked cells; shocked cells retained their viability. Storage of unshocked batch-grown cells in buffer at 10 C led to an increase in ability to accumulate glucosamine, and further experiments were confined to cells grown in a chemostat under conditions of glucose limitation, thereby obviating the need for storing cells before use. A study was made of the effect of the different stages in the cold osmotic shock procedure, including the osmotic stress, the chelating agent, and the cold Mg(2+)-containing diluent, on viability and solute-accumulating ability. Growth of shocked cells in defined medium resembled that of unshocked cells; however, in malt extract-yeast extract-glucose-peptone medium, the shocked cells had a longer lag phase of growth and initially grew at a slower rate. Cold osmotic shock caused the release of low-molecular-weight compounds and about 6 to 8% of the cell protein. Neither the cell envelope enzymes, invertase, acid phosphatase and l-leucine-beta-naphthylamidase, nor the cytoplasmic enzyme, alkaline phosphatase, were released when yeast cells were subjected to cold osmotic shock.
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000613:Aminobutyrates / Q000378:metabolism; D002247:Carbon Isotopes; D002712:Chlorides; D003080:Cold Temperature; D003470:Culture Media; D004492:Edetic Acid; D005944:Glucosamine / Q000378:metabolism; D007202:Indicators and Reagents; D007931:Leucyl Aminopeptidase / Q000378:metabolism; D008274:Magnesium; D008353:Mannitol; D009995:Osmosis; D011506:Proteins / Q000378:metabolism; D012440:Saccharomyces / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D013393:Sucrase / Q000378:metabolism; D013997:Time Factors
chemical_list: D000613:Aminobutyrates; D002247:Carbon Isotopes; D002712:Chlorides; D003470:Culture Media; D007202:Indicators and Reagents; D011506:Proteins; D008353:Mannitol; D004492:Edetic Acid; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D013393:Sucrase; D007931:Leucyl Aminopeptidase; D008274:Magnesium; D005944:Glucosamine