title: Proteome analysis of recombinant xylose-fermenting Saccharomyces cerevisiae.
abstract: Introduction of an active xylose utilization pathway into Saccharomyces cerevisiae, which does not naturally ferment pentose sugars, is likely to have a major impact on the overall cellular metabolism as the carbon introduced to the cells will now flow through the pentose phosphate pathway. The metabolic responses in the recombinant xylose-fermenting S. cerevisiae were studied at the proteome level by comparative two-dimensional gel electrophoresis of cellular proteins within a pH range of 3-10. Glucose-limited chemostat cultivations and corresponding chemostat cultivations performed in media containing xylose as the major carbon source were compared. The cultivations were studied in aerobic and anaerobic metabolic steady states and in addition at time points 5, 30 and 60 min after the switch-off of oxygen supply. We identified 22 proteins having a significant abundance difference on xylose compared to glucose, and 12 proteins that responded to change from aerobic to anaerobic conditions on both carbon sources. On xylose in all conditions studied, major changes were seen in the abundance of alcohol dehydrogenase 2 (Adh2p), acetaldehyde dehydrogenases 4 and 6 (Ald4p and Ald6p), and DL-glycerol 3-phosphatase (Gpp1p). Our results give indications of altered metabolic fluxes especially in the acetate and glycerol pathways in cells growing on xylose compared to glucose.
authors.affiliation: VTT Biotechnology, PO Box 1500, FIN-02044 VTT, Finland. laura.salusjarvi@vtt.fi
authors.forename: Laura
authors.initials: L
authors.lastname: Salusjärvi
authors.forename: Marjo
authors.initials: M
authors.lastname: Poutanen
authors.forename: Juha-Pekka
authors.initials: JP
authors.lastname: Pitkänen
authors.forename: Heini
authors.initials: H
authors.lastname: Koivistoinen
authors.forename: Aristos
authors.initials: A
authors.lastname: Aristidou
authors.forename: Nisse
authors.initials: N
authors.lastname: Kalkkinen
authors.forename: Laura
authors.initials: L
authors.lastname: Ruohonen
authors.forename: Merja
authors.initials: M
authors.lastname: Penttilä
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D019149:Bioreactors; D015180:Electrophoresis, Gel, Two-Dimensional; D005285:Fermentation; D005656:Fungal Proteins / Q000032:analysis / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007218:Industrial Microbiology; D010084:Oxidation-Reduction; D010427:Pentose Phosphate Pathway / Q000502:physiology*; D020543:Proteome / Q000032:analysis* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014994:Xylose / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D020543:Proteome; D014994:Xylose; D005947:Glucose