Saccharomyces cerevisiae engineered to produce D-xylonate

Research output: Contribution to journalArticle

Researchers

  • Mervi H. Toivari
  • Laura Ruohonen
  • Peter Richard
  • Merja Penttila
  • Marilyn G. Wiebe

Research units

  • VTT Technical Research Centre of Finland

Abstract

Saccharomyces cerevisiae was engineered to produce D-xylonate by introducing the Trichoderma reesei xyd1 gene, encoding a D-xylose dehydrogenase. D-xylonate was not toxic to S. cerevisiae, and the cells were able to export D-xylonate produced in the cytoplasm to the supernatant. Up to 3.8 g of D-xylonate per litre, at rates of 25-36 mg of D-xylonate per litre per hour, was produced. Up to 4.8 g of xylitol per litre was also produced. The yield of D-xylonate from D-xylose was approximately 0.4 g of D-xylonate per gramme of D-xylose consumed. Deletion of the aldose reductase encoding gene GRE3 in S. cerevisiae strains expressing xyd1 reduced xylitol production by 67%, increasing the yield of D-xylonate from D-xylose. However, D-xylose uptake was reduced compared to strains containing GRE3, and the total amount of D-xylonate produced was reduced. To determine whether the co-factor NADP(+) was limiting for D-xylonate production the Escherichia coli transhydrogenase encoded by udhA, the Bacillus subtilis glyceraldehyde 3-phosphate dehydrogenase encoded by gapB or the S. cerevisiae glutamate dehydrogenase encoded by GDH2 was co-expressed with xyd1 in the parent and GRE3 deficient strains. Although each of these enzymes enhanced NADPH consumption on D-glucose, they did not enhance D-xylonate production, suggesting that NADP(+) was not the main limitation in the current D-xylonate producing strains.

Details

Original languageEnglish
Pages (from-to)751-760
Number of pages10
JournalApplied Microbiology and Biotechnology
Volume88
Issue number3
Publication statusPublished - Oct 2010
MoE publication typeA1 Journal article-refereed

    Research areas

  • D-xylonic acid, D-xylose, S. cerevisiae, Phosphoglucose isomerase, Redox balance, D-XYLOSE METABOLISM, L-LACTIC ACID, GLUCONOBACTER-OXYDANS, YEAST, REDUCTASE, GENE, DEHYDROGENASE, STRAINS, ALDOSE, IDENTIFICATION

ID: 9228956