The osmotic responses of Saccharomyces cerevisiae in K+-depleted medium

Authors

  • Amanda J. Meikle,

    1. Department of Biological Sciences, University of Dundee, Dundee, Scotland, U.K.
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  • Robert H. Reed,

    1. Department of Biological Sciences, University of Dundee, Dundee, Scotland, U.K.
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    • *

      Department of Chemical and Life Sciences, Newcastle Polytechnic, Newcastle-upon-Type NE1 8ST, U.K.

  • Geoffrey M. Gadd

    Corresponding author
    1. Department of Biological Sciences, University of Dundee, Dundee, Scotland, U.K.
      1Correspondence to: G. M. Gadd, Department of Biological Sciences, University of Dundee, Dundee DD1 4HN, U.K.
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1Correspondence to: G. M. Gadd, Department of Biological Sciences, University of Dundee, Dundee DD1 4HN, U.K.

Summary

Saccharomyces cerevisiae showed reduced growth in a K+-depleted medium but was still capable of synthesizing and accumulating glycerol in the presence of 2.28% (w/v) NaCl; glycerol levels were similar in both K+-replete and K+-depleted media. The activity of glycerol-3-phosphate dehydrogenase, a key enzyme of glycerol synthesis, was inhibited to a similar extent by exogenous K+ and Na+ although such effects may be modified in vivo due to ionic compartmentation within the vacuole. These results indicate that exogenous K+ does not play a significant role in the initiation of glycerol synthesis in osmotically-stressed yeast.

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