Synthesis of long-chain polyunsaturated fatty acids by recombinant cell
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. A process for producing oil containing eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid, comprising the steps of (i) obtaining a transgenic seed of an oilseed plant which comprises eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid in an esterified form as part of triglycerides, wherein the total fatty acid of the transgenic seed comprises at least 2.5% ω3 C20 fatty acids (w/w) and wherein the docosapentaenoic acid is present at a level based on a conversion ratio of eicosapentaenoic acid to docosapentaenoic acid of at least 5% (w/w), (ii) extracting oil from the transgenic seed, and (iii) purifying the extracted oil or treating the extracted oil by hydrolysis, fractionation or distillation.
2. The process of claim 1 , wherein the step of extracting the oil comprises crushing the seed.
3. The process of claim 1 , wherein the total fatty acid of the seed comprises at least 9% C20 fatty acids (w/w).
4. The process of claim 1 , wherein the total fatty acid of the seed comprises at least 1.5% eicosapentaenoic acid and at least 0.13% docosapentaenoic acid (w/w).
5. The process of claim 1 , wherein the total fatty acid of the seed comprises at least 2.1% eicosapentaenoic acid and less than 0.1% eicosatrienoic acid (w/w).
6. The process of claim 1 , wherein at least 25% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
7. The process of claim 1 , wherein at least 50% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
8. The process of claim 1 , wherein the extracted oil comprises at least 50% triacylglycerols.
9. The process of claim 1 , wherein the total fatty acid of the seed comprises at least 7.9% C20 fatty acids (w/w).
10. The process of claim 9 , wherein the total fatty acid of the seed comprises at least 10.2% C20 fatty acids (w/w).
11. The process of claim 10 , wherein the total fatty acid of the seed comprises at least 1.5% eicosapentaenoic acid and at least 0.13% docosapentaenoic acid (w/w).
12. The process of claim 10 , wherein at least 50% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
13. The process of claim 1 , wherein the docosapentaenoic acid is present at a level based on a conversion ratio of eicosapentaenoic acid to docosapentaenoic acid of at least 7% (w/w).
14. The process of claim 13 , wherein the total fatty acid of the seed comprises at least 1.5% eicosapentaenoic acid and at least 0.13% docosapentaenoic acid (w/w).
15. The process of claim 13 , wherein at least 50% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
16. The process of claim 13 , wherein the docosapentaenoic acid is present at a level based on a conversion ratio of eicosapentaenoic acid to docosapentaenoic acid of at least 10% (w/w).
17. The process of claim 16 , wherein the total fatty acid of the seed comprises at least 1.5% eicosapentaenoic acid and at least 0.13% docosapentaenoic acid (w/w).
18. The process of claim 16 , wherein at least 50% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
19. The process of claim 13 , wherein the extracted oil is purified after extraction.
20. The process of claim 16 , wherein the extracted oil is purified after extraction.
21. The process of claim 1 , wherein the triacylglycerols in the extracted oil are hydrolysed after extraction.
22. The process of claim 1 , wherein the oilseed plant is a Brassica plant.
23. The process of claim 13 , wherein the oilseed plant is a Brassica plant.
24. The process of claim 16 , wherein the oilseed plant is a Brassica plant.
25. The process of claim 23 , wherein the Brassica plant is a canola plant.
26. A process for producing a composition comprising eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid, comprising the steps of (i) obtaining a transgenic seed of an oilseed plant which comprises eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid in an esterified form as part of triglycerides, wherein the total fatty acid of the transgenic seed comprises at least 2.5% ω3 C20 fatty acids (w/w) and wherein the docosapentaenoic acid is present at a level based on a conversion ratio of eicosapentaenoic acid to docosapentaenoic acid of at least 5% (w/w), (ii) extracting oil from the transgenic seed, and (iii) processing the oil, thereby producing the composition.
27. The process of claim 26 , wherein the total fatty acid of the seed comprises at least 1.5% eicosapentaenoic acid and at least 0.13% docosapentaenoic acid (w/w).
28. The process of claim 26 , wherein the total fatty acid of the seed comprises at least 2.1% eicosapentaenoic acid and less than 0.1% eicosatrienoic acid (w/w).
29. The process of claim 26 , wherein at least 50% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
30. The process of claim 26 , wherein the extracted oil comprises at least 50% triacylglycerols.
31. The process of claim 26 , wherein the total fatty acid of the seed comprises at least 7.9% C20 fatty acids (w/w).
32. The process of claim 31 , wherein the total fatty acid of the seed comprises at least 10.2% C20 fatty acids (w/w).
33. The process of claim 32 , wherein the total fatty acid of the seed comprises at least 1.5% eicosapentaenoic acid and at least 0.13% docosapentaenoic acid (w/w).
34. The process of claim 32 , wherein at least 50% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
35. The process of claim 26 , wherein the docosapentaenoic acid is present at a level based on a conversion ratio of eicosapentaenoic acid to docosapentaenoic acid of at least 7% (w/w).
36. The process of claim 35 , wherein the total fatty acid of the seed comprises at least 1.5% eicosapentaenoic acid and at least 0.13% docosapentaenoic acid (w/w).
37. The process of claim 35 , wherein at least 50% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
38. The process of claim 35 , wherein the docosapentaenoic acid is present at a level based on a conversion ratio of eicosapentaenoic acid to docosapentaenoic acid of at least 10% (w/w).
39. The process of claim 38 , wherein the total fatty acid of the seed comprises at least 1.5% eicosapentaenoic acid and at least 0.13% docosapentaenoic acid (w/w).
40. The process of claim 38 , wherein at least 50% (w/w) of the eicosapentaenoic acid and docosapentaenoic acid of the seed is incorporated into triacylglycerols in the seed.
41. The process of claim 35 , wherein the extracted oil is purified after extraction.
42. The process of claim 38 , wherein the extracted oil is purified after extraction.
43. The process of claim 26 , wherein the triacylglycerols in the extracted oil are hydrolysed after extraction.
44. The process of claim 26 , wherein the oilseed plant is a Brassica plant.
45. The process of claim 35 , wherein the oilseed plant is a Brassica plant.
46. The process of claim 38 , wherein the oilseed plant is a Brassica plant.
47. The process of claim 45 , wherein the Brassica plant is a canola plant.