Transcriptional control of ADH genes in the xylose-fermenting yeast Pichia stipitis

Journal Article · Tue Jun 01 04:00:00 EDT 1999 · Applied and Environmental Microbiology

OSTI ID:354324

Cho, J Y; Jeffries, T W ^[1]

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1. Forest Service, Madison, WI (United States). Forest Products Lab.

The authors studied the expression of the genes encoding group 1 alcohol dehydrogenases (PsADH1 and PsADH2) in the xylose-fermenting yeast Pichia stipitis CBS 6054. The cells expressed PsADH1 approximately 10 times higher under oxygen-limited conditions than under fully aerobic conditions when cultivated on xylose. Transcripts of PsADH2 were not detectable under either aeration condition. The authors used a PsADH1::lacZ fusion to monitor PsADH1 expression and found that expression increased as oxygen decreased. The level of PsADH1 transcript was expressed about 10-fold in cells grown in the presence of heme under oxygen-limited conditions. Concomitantly with the induction of PsADH1, PsCYC1 expression was regressed. These results indicate that oxygen availability regulates PsADH1 expression and that regulation may be mediated by heme. The regulation of PsADH2 expression was also examined in other genetic backgrounds. Disruption of PsADH1 dramatically increased PsADH2 expression on nonfermentable carbon sources under fully aerobic conditions, indicating that the expression of PsADH2 is subject to feedback regulation under these conditions.

• Sponsoring Organization: National Renewable Energy Lab., Golden, CO (United States); Department of Agriculture, Washington, DC (United States)
• OSTI ID: 354324
• Journal Information: Applied and Environmental Microbiology, Journal Name: Applied and Environmental Microbiology Journal Issue: 6 Vol. 65; ISSN AEMIDF; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
ALCOHOL DEHYDROGENASE
FERMENTATION
GENE REGULATION
TRANSCRIPTION
XYLOSE
YEASTS