Yeast cells genetically modified for downregulation of pyruvate decarboxylase activity and FBP-sensitive pyruvate kinase
A fungal cell capable of producing high levels of fatty acids and fatty acid-derived products comprises at least one modification to the endogenous fatty acid metabolism.
1. A yeast cell, wherein
pyruvate decarboxylase activity in said yeast cell is downregulated by the deletion of at least one gene selected from the group consisting of PDC1, PDC5 and PDC6; and
said yeast cell is further genetically modified for
downregulation of an endogenous fructose-1,6-bisphosphate (FBP)-sensitive pyruvate kinase PYK1; and/or
overexpression of an endogenous fructose-1,6-bisphosphate (FBP)-insensitive pyruvate kinase PYK2, wherein
said yeast cell has reduced ethanol formation compared to an unmodified yeast cell by said deletion of at least one gene selected from the group consisting of PDC1, PDC5 and PDC6; and
said yeast cell is able to grow on glucose as a carbon source by said downregulation of said endogenous PYK1 and/or said overexpression of said endogenous PYK2.
2. The yeast cell according to claim 1 , wherein said yeast cell is genetically modified for overexpression of an endogenous acetyl-CoA carboxylase.
3. The yeast cell according to claim 1 , wherein said yeast cell is genetically modified for overexpression of an endogenous pyruvate carboxylase.
4. The yeast cell according to claim 1 , wherein said yeast cell is further genetically modified for overexpression of at least one protein selected from the group consisting of a mitochondrial pyruvate carrier, a citrate synthase and a citrate and oxoglutarate carrier protein.
5. The yeast cell according to claim 4 , wherein said mitochondrial pyruvate carrier is selected from the group consisting of MPC1 and MPC3.
6. The yeast cell according to claim 4 , wherein said citrate synthase is selected from the group consisting of Rhodosporidium toruloides citrate synthase RtCIT1 and Saccharomyces cerevisiae citrate synthase ScCIT1.
7. The yeast cell according to claim 4 , wherein said citrate and oxoglutarate carrier protein is YHM2.
8. The yeast cell according to claim 1 , wherein said yeast cell is genetically modified for overexpression of a gene selected from the group consisting of MPP6, ACP1, EPT1, FAA1, GEP4, GGA2, IDP3, INP54, LPP1, MCR1, ORMI, RTC3, SPO7, TGL1 and YFT2.
9. The yeast cell according to claim 8 , wherein said yeast cell is genetically modified for overexpression of GGA2.
10. The yeast cell according to claim 1 , wherein said yeast cell is a yeast cell selected from the group consisting of Saccharomyces, Kluyveromyces, Zygosaccharomyces, Candida, Hansenula, Torulopsis, Kloeckera, Pichia, Schizosaccharomyces , Trigonopsis, Brettanomyces, Debaromyces, Nadsonia, Lipomyces, Cryptococcus, Aureobasidium, Trichosporon, Lipomyces, Rhodotorula, Yarrowia , Rhodosporidium, Phaffia, Schwanniomyces, Aspergillus , and Ashbya.
11. The yeast cell according to claim 10 , wherein said yeast cell is a yeast cell selected from the group consisting of Saccharomyces cerevisiae, Pichia pastoris, Ashbya gossypii, Saccharomyces boulardii, Zygosaccharomyces bailii, Kluyveromyces lactis , Rhodosporidium toruloides and Yarrowia lipolytica.
12. A method for producing a fatty acid comprising:
culturing a yeast cell according to claim 1 in a culture medium and in culture conditions suitable for production of said fatty acid by said yeast cell, and
collecting said fatty acid from said culture medium and/or said yeast cell,
wherein the yeast cell according to claim 1 is genetically modified for overexpression of an endogenous acetyl-CoA carboxylase and genetically modified for overexpression of an endogenous pyruvate carboxylase.
13. A method for producing a fatty acid derived-product comprising:
culturing a yeast cell according claim 1 in a culture medium and in culture conditions suitable for production of said fatty acid-derived product by said yeast cell; and
collecting said fatty acid-derived product from said culture medium and/or said yeast cell,
wherein said fatty acid-derived product is selected from the group consisting of a hydrocarbon, a triacylglyceride, a phospholipid, a lactone, a fatty alcohol, a fatty aldehyde, a fatty acid ester, and a mixture thereof, and
wherein the yeast cell according to claim 1 is genetically modified for overexpression of an endogenous acetyl-CoA carboxylase and genetically modified for overexpression of an endogenous pyruvate carboxylase.