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An Examination of the Crabtree Effect in Saccharomyces cerevisiae: the Role of Respiratory Adaptation

1979; Microbiology Society; Volume: 114; Issue: 2 Linguagem: Inglês

10.1099/00221287-114-2-267

2059-9323

J. P. Barford, Robert J. Hall,

Microbial Metabolic Engineering and Bioproduction

The control of glycolysis and respiration in a strain of baker's yeast was quantified, including, for the first time, corrections obtained from carbon and redox balances which allowed for interactions between anabolism and catabolism. When these corrections were applied, no repression of respiration was observed during fully adapted growth in continuous culture; however, the rate of respiration reached a maximum value, independent of the nature of the energy substrate, at a specific growth rate less than the maximum specific growth rate of the organism. During batch growth, considerable adaptation was necessary for this organism to achieve its maximum respiratory capacity. Further, this adaptation was extremely slow, particularly when glucose or maltose was the limiting substrate, and its full extent was frequently not achieved. Consequently, a residual repression, presumably originally caused by growth under restricted aeration in shake flasks, was observed during batch growth.