Central carbon metabolism of Saccharomyces cerevisiae in anaerobic, oxygen-limited and fully aerobic steady-state conditions and following a shift to anaerobic conditions.
Saccharomyces cerevisiae CEN.PK113-1A was grown in glucose-limited chemostat culture with 0%, 0.5%, 1.0%, 2.8% or 20.9% O2 in the inlet gas (D=0.10 h(-1), pH 5, 30 degrees C) to determine the effects of oxygen on 17 metabolites and 69 genes related to central carbon metabolism. The concentrations of tricarboxylic acid cycle (TCA) metabolites and all glycolytic metabolites except 2-phosphoglycerate+3-phosphoglycerate and phosphoenolpyruvate were higher in anaerobic than in fully aerobic conditions. Provision of only 0.5-1% O2 reduced the concentrations of most metabolites, as compared with anaerobic conditions. Transcription of most genes analyzed was reduced in 0%, 0.5% or 1.0% O2 relative to cells grown in 2.8% or 20.9% O2. Ethanol production was observed with 2.8% or less O2. After steady-state analysis in defined oxygen concentrations, the conditions were switched from aerobic to anaerobic. Metabolite and transcript levels were monitored for up to 96 h after the transition, and this showed that more than 30 h was required for the cells to fully adapt to anaerobiosis. Levels of metabolites of upper glycolysis and the TCA cycle increased following the transition to anaerobic conditions, whereas those of metabolites of lower glycolysis generally decreased. Gene regulation was more complex, with some genes showing transient upregulation or downregulation during the adaptation to anaerobic conditions.
Wiebe
Marilyn G
MG
VTT Technical Research Centre of Finland, Finland. marilyn.wiebe@vtt.fi
Rintala
Eija
E
Tamminen
Anu
A
Simolin
Helena
H
Salusjärvi
Laura
L
Toivari
Mervi
M
Kokkonen
Juha T
JT
Kiuru
Jari
J
Ketola
Raimo A
RA
Jouhten
Paula
P
Huuskonen
Anne
A
Maaheimo
Hannu
H
Ruohonen
Laura
L
Penttilä
Merja
M
D000332:Aerobiosis; D000693:Anaerobiosis; D002244:Carbon; D002952:Citric Acid Cycle; D003470:Culture Media / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis; D053858:Metabolic Networks and Pathways; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
D003470:Culture Media; D029701:Saccharomyces cerevisiae Proteins; D002244:Carbon; D005947:Glucose; D010100:Oxygen