Synthesis of long-chain polyunsaturated fatty acids by recombinant cells
View Patent ↗The present invention relates to methods of synthesizing long-chain polyunsaturated fatty acids, especially eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid, in recombinant cells such as yeast or plant cells. Also provided are recombinant cells or plants which produce long-chain polyunsaturated fatty acids. Furthermore, the present invention relates to a group of new enzymes which possess desaturase or elongase activity that can be used in methods of synthesizing long-chain polyunsaturated fatty acids.
1. An Arabidopsis thaliana or Glycine max plant cell comprising
docosapentaenoic acid and docosahexaenoic acid in an esterified form as part of triacylglycerols in the plant cell;
a polynucleotide which encodes a Δ5 elongase operably linked to a promoter which directs expression of the polynucleotide in the plant cell;
a polynucleotide which encodes a Δ4 desaturase operably linked to a promoter which directs expression of the polynucleotide in the plant cell;
a desaturase which desaturates an acyl-CoA substrate in the plant cell; and
a total fatty acid content in the plant cell which includes 2.5% (w/w) C20 ω3 long-chain polyunsaturated fatty acids (LC-PUFAs) and 0.1% (w/w) docosapentaenoic acid.
2. The plant cell of claim 1 , wherein 50% of the docosapentaenoic acid in the plant cell is incorporated into triacylglycerols.
3. The plant cell of claim 1 , wherein 50% of the docosahexaenoic acid in the plant cell is incorporated into triacylglycerols.
4. The plant cell of claim 1 , wherein the total fatty acid content in the plant cell comprises 0.13% (w/w) docosapentaenoic acid.
5. The plant cell of claim 1 , wherein the total fatty acid content in the plant cell comprises at least 0.5% (w/w) docosapentaenoic acid.
6. The plant cell of claim 1 , wherein the desaturase which desaturates an acyl-CoA substrate is Δ5 desaturase or Δ6 desaturase.
7. The plant cell of claim 1 , wherein the desaturase which desaturates an acyl-CoA substrate is Δ5 desaturase and Δ6 desaturase.
8. The plant cell of claim 1 , further comprising a polynucleotide encoding a Δ5 desaturase, a polynucleotide encoding a Δ6 desaturase, and a polynucleotide encoding a Δ6 elongase, each polynucleotide operably linked to a promoter capable of directing expression of the polynucleotide in the plant cell.
9. The plant cell of claim 1 , further comprising a polynucleotide encoding a Δ5 desaturase, a polynucleotide encoding a Δ8 desaturase, and a polynucleotide encoding a Δ9 elongase, each polynucleotide operably linked to a promoter capable of directing expression of the polynucleotide in the plant cell.
10. The plant cell of claim 1 , comprising a C20 ω3 long-chain polyunsaturated fatty acid which is eicosapentaenoic acid.
11. The plant cell of claim 1 , wherein the cell is homozygous for each polynucleotide.
12. The plant cell of claim 1 , wherein the cell is a Glycine max plant cell.
13. An Arabidopsis thaliana or Glycine max plant seed comprising the Arabidopsis thaliana or Glycine max plant cell, respectively, of claim 1 .
14. The seed of claim 13 , wherein the seed is homozygous for each polynucleotide.
15. An Arabidopsis thaliana or Glycine max plant comprising the cell of claim 1 .
16. A process of preparing oil comprising
obtaining the Arabidopsis thaliana or Glycine max plant seed of claim 13 ; and
extracting oil from the seed.