Structuring fats and methods of producing structuring fats
Recombinant DNA techniques are used to produce oleaginous recombinant cells that produce triglyceride oils having desired fatty acid profiles and regiospecific or stereospecific profiles. Genes manipulated include those encoding stearoyl-ACP desturase, delta 12 fatty acid desaturase, acyl-ACP thioesterase, ketoacyl-ACP synthase, and lysophosphatidic acid acyltransferase. The oil produced can have enhanced oxidative or thermal stability, or can be useful as a frying oil, shortening, roll-in shortening, tempering fat, cocoa butter replacement, as a lubricant, or as a feedstock for various chemical processes. The fatty acid profile can be enriched in midchain profiles or the oil can be enriched in triglycerides of the saturated-unsaturated-saturated type.
1. A recombinant microalgal cell, the cell comprising exogenous nucleic acids encoding a C16:0 or C18:0 preferring acyl-ACP thioesterase A (FATA), wherein the oil produced by the recombinant microalgal cell is enriched in stearic-oleic-stearic (SOS), palmitic-oleic-palmitic (POP) and/or palmitic-oleic-stearic (POS) triglycerides, as compared to non-recombinant microalgal cells.
2. The recombinant microalgal cell of claim 1 , wherein the C16:0 or C18:0 preferring acyl-ACP thioesterase A is a Brassica FATA or a Garcinia FATA.
3. The recombinant microalgal cell of claim 2 , wherein the C16:0 or C18:0 preferring acyl-ACP thioesterase A is a Garcinia FATA.
4. The recombinant microalgal cell of claim 3 , wherein the C16:0 or C18:0 preferring acyl-ACP thioesterase A is a Garcinia mangostana FATA.
5. The method of claim 2 , wherein the C16:0 or C18:0 preferring acyl-ACP thioesterase A is a Brassica FATA.
6. The recombinant microalgal cell of claim 1 , wherein the recombinant microalgal cell further comprises nucleic acids that encode sucrose invertase.
7. The recombinant microalgal cell of claim 1 , wherein the oil produced by the recombinant microalgal cell comprises at least 50% SOS, or optionally at least 70% SOS.
8. The recombinant microalgal cell of claim 1 , wherein the microalgal cell is of the genus Prototheca or Chlorella.
9. The recombinant microalgal cell of claim 8 , wherein the microalgal cell is of the species Prototheca moriformis.
10. The recombinant microalgal cell of claim 1 , wherein the exogenous nucleic acids are codon optimized for expression in a cell of the genus Prototheca.
11. A method of producing a microalgal oil enriched in stearic-oleic-stearic (SOS), palmitic-oleic-palmitic (POP) and/or palmitic-oleic-stearic (POS) triglycerides, as compared to non-recombinant microalgal cells, the method comprising the steps of:
a) providing a recombinant microalgal cell, the cell comprising exogenous nucleic acids encoding a C16:0 or C18:0 preferring acyl-ACP thioesterase A (FATA);
b) cultivating the recombinant microalgal cell; and
c) isolating the microalgal oil from the microalgal cell.
12. The method of claim 11 , wherein the C16:0 or C18:0 preferring acyl-ACP thioesterase A is a Brassica FATA or a Garcinia FATA.
13. The method of claim 12 , wherein the C16:0 or C18:0 preferring acyl-ACP thioesterase A is a Garcinia FATA.
14. The method of claim 3 , wherein the C16:0 or C18:0 preferring acyl-ACP thioesterase A is a Garcinia mangostana FATA.
15. The method of claim 12 , wherein the C16:0 or C18:0 preferring acyl-ACP thioesterase A is a Brassica FATA.
16. The recombinant microalgal cell of claim 11 , wherein the recombinant microalgal cell further comprises nucleic acids that encode sucrose invertase.
17. The method of claim 11 , wherein the oil produced by the recombinant microalgal cell comprises at least 50% SOS, or optionally at least 70% SOS.
18. The method of claim 11 , wherein the microalgal cell is of the genus Prototheca or Chlorella.
19. The method of claim 18 , wherein the microalgal cell is of the species Prototheca moriformis.
20. The method of claim 11 , wherein the exogenous nucleic acids are codon optimized for expression in a cell of the genus Prototheca.