Methods of producing lipids
The present invention relates to methods of producing lipids. In particular, the present invention relates to methods of increasing the level of one or more non-polar lipids and/or the total non-polar lipid content in a transgenic organism or part thereof. In one particular embodiment, the present invention relates to the use of an acyltransferase, for example, a monoacylglycerol acyltransferase (MGAT) to increase the level of one or more non-polar lipids and/or the total non-polar lipid content in plants, plant seed and/or leaves, algae and fungi.
1. A method of producing extracted lipid, the method comprising the steps of:
a) selecting a vegetative part of a plant or a unicellular plant
i) expressing an exogenous monoacylglycerol acyltransferase (MGAT); and
ii) comprising a level of triacylglycerol (TAG) that is greater on a relative basis when compared to such a vegetative part of a plant or unicellular plant lacking the exogenous MGAT, and
b) extracting lipid from the plant, thereby producing the extracted lipid.
2. The method of claim 1 , wherein the level of TAG in the vegetative part of the plant or unicellular plant is at least 10% greater on a relative basis when compared to such a vegetative part of a plant or unicellular plant lacking the exogenous MGAT.
3. The method of claim 2 , wherein the level of TAG in the vegetative part of the plant or unicellular plant is at least 30% greater on a relative basis when compared to such a vegetative part of a plant or unicellular plant lacking the exogenous MGAT.
4. The method of claim 3 , wherein the level of TAG in the vegetative part of the plant or unicellular plant is at least 90% greater on a relative basis when compared to such a vegetative part of a plant or unicellular plant lacking the exogenous MGAT.
5. The method of claim 1 , wherein the plant is Brassica sp., Gossypium hirsutum, Linum usitatissimum, Helianthus sp., Carthamus tinctorius, Glycine max, Zea mays, Arabidopsis thaliana, Sorghum bicolor, Sorghum vulgare, Avena sativa, Trifolium sp., Camelina sativa, Miscanthus×giganteus , or Miscanthus sinensis.
6. The method of claim 1 , wherein the plant is an aquatic plant.
7. The method of claim 1 , wherein the plant is a unicellular plant.
8. The method of claim 1 , wherein a vegetative part of a plant is selected.
9. The method of claim 8 , wherein the TAG, diacylglycerol (DAG), TAG and DAG, or monoacylglycerol (MAG) content of the vegetative part of the plant is at least 10% greater on a relative basis than the TAG, DAG, TAG and DAG, or MAG content of a corresponding vegetative part of a plant lacking the exogenous MGAT.
10. The method of claim 1 , wherein at least 60% (mol %) of the fatty acid content of the extracted lipid is oleic acid.
11. The method of claim 1 , wherein the polyunsaturated fatty acid content of the extracted lipid is increased when compared to the polyunsaturated fatty acid content of a plant lacking the exogenous MGAT.
12. The method of claim 1 , wherein the method further comprises determining the level of TAG in the extracted lipid by analysis, wherein the analysis comprises gas chromatography of fatty acid methyl esters obtained from the extracted lipid.
13. The method of claim 1 , wherein the plant is other than a unicellular plant, and extracting lipid from the plant is extracting lipid from a part of the plant.
14. The method of claim 8 , wherein the method further comprises harvesting seed from the plant.
15. The method of claim 8 , wherein the plant comprises seed, and step b) comprises pressing seedoil from seed.
16. The method of claim 1 which further comprises reacting the extracted lipid with an alcohol, optionally in the presence of a catalyst, to produce alkyl esters.
17. The method of claim 16 which further comprises blending the alkyl esters with petroleum based fuel.
18. The method of claim 1 , wherein the plant or vegetative part of the plant or unicellular plant further comprises an exogenous glycerol-3-phosphate acyltransferase (GPAT).
19. The method of claim 18 , wherein the exogenous GPAT has phosphatase activity to produce MAG.
20. The method of claim 19 , wherein the level of TAG in the vegetative part of the plant or unicellular plant is at least 10% greater on a relative basis when compared to such a vegetative part of a plant or unicellular plant lacking the exogenous MGAT.