Pyruvate decarboxylase: an indispensable enzyme for growth of Saccharomyces cerevisiae on glucose

Yeast. 1996 Mar 15;12(3):247-57. doi: 10.1002/(SICI)1097-0061(19960315)12:3%3C247::AID-YEA911%3E3.0.CO;2-I.


In Saccharomyces cerevisiae, the structural genes PDC1, PDC5 and PDC6 each encode an active pyruvate decarboxylase. Replacement mutations in these genes were introduced in a homothallic wild-type strain, using the dominant marker genes APT1 and Tn5ble. A pyruvate-decarboxylase-negative (Pdc-) mutant lacking all three PDC genes exhibited a three-fold lower growth rate in complex medium with glucose than the isogenic wild-type strain. Growth in batch cultures on complex and defined media with ethanol was not impaired in Pdc- strains. Furthermore, in ethanol-limited chemostat cultures, the biomass yield of Pdc- and wild-type S. cerevisiae were identical. However, Pdc- S. cerevisiae was unable to grow in batch cultures on a defined mineral medium with glucose as the sole carbon source. When aerobic, ethanol-limited chemostat cultures (D = 0 center dot 10 h-1) were switched to a feed containing glucose as the sole carbon source, growth ceased after approximately 4 h and, consequently, the cultures washed out. The mutant was, however, able to grow in chemostat cultures on mixtures of glucose and small amounts of ethanol or acetate (5% on a carbon basis). No growth was observed when such cultures were used to inoculate batch cultures on glucose. Furthermore, when the mixed-substrate cultures were switched to a feed containing glucose as the sole carbon source, wash-out occurred. It is concluded that the mitochondrial pyruvate dehydrogenase complex cannot function as the sole source of acetyl-CoA during growth of S. cerevisiae on glucose, neither in batch cultures nor in glucose-limited chemostat cultures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Culture Media
  • Glucose / metabolism*
  • Mutation
  • Pyruvate Decarboxylase / physiology*
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / growth & development*


  • Culture Media
  • Pyruvate Decarboxylase
  • Glucose