Transgenic microalgae with increased production of at least one omega-3 long chain polyunsaturated fatty acid

1. A transgenic microalgae with increased production of at least one omega-3 long chain polyunsaturated fatty acid (LC-PUFA) compared to a control microalgae,

wherein the transgenic microalgae overexpresses a nucleic acid encoding a Δ5-elongase and/or Δ6-desaturase, wherein the nucleic acid encoding the Δ5-elongase is selected from SEQ ID NO:1 and a sequence that encodes a Δ5-elongase that has at least 75% homology to SEQ ID NO:2, and wherein the nucleic acid encoding a Δ6-desaturase is selected from SEQ ID NO:3; a sequence that encodes a Δ6-desaturase that has at least 75% homology to SEQ ID NO:4; SEQ ID NO:5; SEQ ID NO:7; a sequence that encodes a Δ6-desaturase that has at least 75% homology to SEQ ID NO:8; SEQ NO:9 and a sequence that encodes a Δ6-desaturase that has at least 75% homology to SEQ ID NO:10;

wherein the omega-3 LC-PUFA is EPA and/or DHA, and wherein, when the omega-3 LC-PUFA is EPA, the increase is to at least 20% of the total fatty acid content, and when the omega-3 LC-PUFA is DHA, the increase is to at least 7% of the total fatty acid content; and

wherein the transgenic microalgae is selected from Phaeodactylum, Nannochloropsis, Thraustochytrium, Schizochytrium , or Thalassiosira.

2. A transgenic microalgae of claim 1 , wherein the nucleic acid further comprises a regulatory sequence.

3. A method for producing transgenic microalgae with an increased omega-3 LC-PUFA content compared to a control microalgae, the method comprising transforming a microalgae with a nucleic acid encoding a Δ5-elongase in order to increase the content of DHA or a nucleic acid encoding Δ6-desaturase in order to increase the content of EPA, wherein said nucleic acid encoding a Δ5-elongase is selected from SEQ ID NO:1 and a sequence that encodes a Δ5-elongase that has at least 75% homology to SEQ ID NO:2, and wherein the nucleic acid encoding a Δ6-desaturase is selected from SEQ NO:3; a sequence that encodes a Δ6-desaturase that has at least 75% homology to SEQ ID NO:4; SEQ ID NO:5; SEQ ID NO:7; a sequence that encodes a Δ6-desaturase that has at least 75% homology to SEQ ID NO:8; SEQ ID NO:9 and a sequence that encodes a Δ6-desaturase that has at least 75% homology to SEQ ID NO:10.

4. A method for increasing production of one or more omega-3 LC-PUFAs in microalgae, the method comprising

a) cultivating a transgenic microalgae of claim 1 under conditions which allow for the production of one or more omega-3 LC-PUFAs and

b) obtaining the one or more omega-3 LC-PUFAs from the transgenic microalgae.

5. A method of claim 4 , wherein the omega-3 LC-PUFA is DHA.

6. A method of claim 4 , wherein the omega-3 LC-PUFA is EPA.

7. A composition comprising a transgenic microalgae of claim 1 .

8. A method for making a feedstuff, the method comprising

a) cultivating a transgenic microalgae of claim 1 under conditions allow for the production of one or more omega-3 LC-PUFAs;

b) obtaining one or more omega-3 LC-PUFAs from the transgenic microalgae; and

c) making a feedstuff from the one or more omega-3 LC-PUFAs.

9. The transgenic microalgae of claim 1 , wherein the control microalgae has not been genetically modified to alter the content of omega-3 LC-PUFAs therein.

10. The transgenic microalgae of claim 1 , wherein the transgenic microalgae is Phaeodactylum.

11. The transgenic microalgae of claim 1 , wherein the omega-3 LC-PUFA is DHA and wherein the increase to at least 10% of the total fatty acid content is in the stationary phase.

12. The transgenic microalgae of claim 1 , wherein the omega-3 LC-PUFA is EPA and wherein the increase to at least 20% of the total fatty acid content is in the stationary phase.