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Updated: Jun 10, 2026
10:10
Genetic Engineering of an Unconventional Yeast for Renewable Biofuel and Biochemical Production
Published on: September 20, 2016
Saccharomyces cerevisiae engineered to produce D-xylonate
Mervi H Toivari1, Laura Ruohonen, Peter Richard
1VTT, Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT Espoo, Finland. mervi.toivari@vtt.fi
Applied Microbiology and Biotechnology
|August 4, 2010
Summary
Engineered yeast produces D-xylonate from D-xylose. Deleting a specific gene improved yield but reduced sugar uptake, while cofactor manipulation did not boost production, indicating NADP+ is not the primary limitation.
Area of Science:
- Biotechnology
- Metabolic Engineering
- Microbial Production
Background:
- Saccharomyces cerevisiae is a key host for microbial production.
- D-xylonate is a valuable chemical with potential applications.
- Engineering yeast for D-xylonate production requires understanding metabolic pathways and limitations.
Purpose of the Study:
- To engineer Saccharomyces cerevisiae for efficient D-xylonate production.
- To investigate the impact of aldose reductase (GRE3) deletion on D-xylonate yield and production rates.
- To assess the role of NADP+ availability as a limiting factor in D-xylonate biosynthesis.
Main Methods:
- Introduction of the Trichoderma reesei xyd1 gene encoding D-xylose dehydrogenase into S. cerevisiae.
- Genetic deletion of the GRE3 gene in engineered yeast strains.
- Co-expression of genes encoding transhydrogenases (udhA, gapB, GDH2) to enhance NADPH regeneration.
- Quantification of D-xylonate and xylitol production, D-xylose consumption, and specific growth rates.
Main Results:
- Engineered S. cerevisiae produced up to 3.8 g/L of D-xylonate at rates of 25-36 mg/L/h.
- Deletion of GRE3 reduced xylitol byproduct formation by 67% and increased D-xylonate yield but decreased D-xylose uptake.
- Co-expression of genes involved in NADPH regeneration did not enhance D-xylonate production, suggesting NADP+ is not the primary limitation.
Conclusions:
- S. cerevisiae can be engineered to produce and export D-xylonate.
- While GRE3 deletion improves D-xylonate yield, it negatively impacts substrate uptake.
- NADP+ availability is likely not the main bottleneck for D-xylonate production in these engineered strains.
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