Modulating the distribution of fluxes among respiration and fermentation by overexpression of HAP4 in Saccharomyces cerevisiae

FEMS Yeast Res. 2001 Jul;1(2):139-49. doi: 10.1111/j.1567-1364.2001.tb00025.x.


The tendency of Saccharomyces cerevisiae to favor alcoholic fermentation over respiration is a complication in aerobic, biomass-directed applications of this yeast. Overproduction of Hap4p, a positive transcriptional regulator of genes involved in respiratory metabolism, has been reported to positively affect the balance between respiration and fermentation in aerobic glucose-grown batch cultures. In this study, the effects of HAP4 overexpression have been quantified in the prototrophic S. cerevisiae strain CEN.PK 113-7D under a variety of growth conditions. In aerobic glucose-limited chemostat cultures, overexpression of HAP4 increased the specific growth rate at which aerobic fermentation set in by about 10% relative to the isogenic wild-type. Upon relief of glucose-limited conditions, the HAP4-overexpressing strain produced slightly less ethanol than the wild-type strain. The effect of Hap4p overproduction was most drastic in aerobic, glucose-grown chemostat cultures in which ammonium was limiting. In such cultures, the biomass yield on glucose was double that of the wild-type.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerobiosis
  • Biomass
  • CCAAT-Binding Factor / genetics
  • CCAAT-Binding Factor / metabolism*
  • Culture Media
  • Ethanol / metabolism*
  • Fermentation
  • Gene Expression Regulation, Fungal*
  • Glucose / metabolism
  • Oxygen Consumption*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / growth & development*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • CCAAT-Binding Factor
  • Culture Media
  • HAP4 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Ethanol
  • Glucose