Engineering fungi for the utilisation of l-arabinose

• US 20030186402A1
• Filed: 03/10/2003
• Published: 10/02/2003
• Est. Priority Date: 02/16/2001
• Status: Active Grant

• Current Assignee: Valtion Teknillinen Tutkimuskeskus
• Original Assignee: Valtion Teknillinen Tutkimuskeskus
• Inventors: Penttilä, Merja, Richard, Peter, Londesborough, John
• Granted Patent: US 7,527,951 B2
• Time in Patent Office: Days
• US Class Current: 435/161
• CPC Class Codes: C12N 9/0006 acting on CH-OH groups as donors (1.1)
• CPC Class Codes: C12Y 101/0101 L-Xylulose reductase (1.1.1.10)
• CPC Class Codes: C12Y 101/01012 L-Arabinitol 4-dehydrogenase (1.1.1.12)
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A fungal microorganism can be engineered by means of genetic engineering to utilise L-arabinose. The genes of the L-arabinose pathway, which were unknown, i.e. L-arabinitol 4-dehydrogenase and L-xylulose reductase, were identified. These genes, together with the known genes of the L-arabinose pathway, form a functional pathway. This pathway can be introduced to a fungus, which is completely or partially lacking this pathway.

Claims

1. A genetically modified fungus having an increased ability to utilise L-arabinose, characterised in that it has been transformed with a DNA sequence encoding an L-arabinitol 4-dehydrogenase or a DNA sequence encoding a L-xylulose reductase or both said DNA sequences.

2. A genetically modified fungus according to claim 1, characterised in that the DNA sequence encoding the L-arabinitol 4-dehydrogenase is SEQ ID NO. 1 or a functionally equivalent variant thereof and the DNA sequence encoding the L-xylulose reductase is SEQ ID NO. 2 or a functionally equivalent variant thereof.

3. A genetically modified fungus according to claims 1 or 2, characterised in that it produces useful products.

4. A genetically modified fungus according to any of claims 1 to 3, characterised in that it produces derivatives of the pentose phosphate pathway or of the fungal L-arabinose pathway, or ethanol, lactic acid, xylitol or arabinitol.

5. A genetically modified fungus according to any of claims 1 to 4, characterised in that the fungus is a yeast.

6. A genetically modified funous according to claim 5, characterised in that the yeast is a strain of Saccharomyces species, Schizosaccharomyces species, Kiuveromyces species, Pichia species, Candida species or Pachysolen species.

7. A genetically modified fungus according to claim 6, characterised in that the strain is a genetically engineered strain of S. cerevisiae.

8. A genetically modified fungus according to any of claims 1 to 4, characterised in that the fungus is a filamentous fungus.

9. A genetically modified fungus according to claim 8, characterised in that the strain is a genetically engineered strain of Aspergillus species, Trichoderma species, Neurospora species, Fusarium species, Penicillium species, Humicola species, Tolypocladium geodes, Trichoderma reesei (Hypocrea jecorina), Mucor species, Trichoderma longibrachiatum, Aspergillus nidulans, Aspergillus niger or Aspergillus awamori.

10. A genetically modified fungus according to any of claims 1 to 9, characterised in that the fungus prior modification is able to utilise D-xylose.

11. A method of producing useful products from biomass containing L-arabinose, characterised in that the product is produced from said biomass by a genetically modified fungus of one of claims 1 to 10.

12. A method according to claim 11, characterised in that the useful product is ethanol, lactic acid or xylitol.

13. A method according to claim 12, characterised in that the useful product is ethanol.

14. An isolated DNA molecule, characterised in that it comprises a gene coding for an L-arabinitol 4-dehydrogenase having the sequence of SEQ ID NO. 1 or a functionally equivalent variant thereof

15. An isolated DNA molecule, characterised in that it comprises a gene coding for an L-xylulose reductase having the sequence SEQ ID NO. 2 or a functionally equivalent variant thereof.