Yeast cell for the production of terpenes and uses thereof

1. A yeast cell, wherein

a) said cell comprises a functional gene coding for soluble hydroxymethylglutaryl-coenzyme-A (HMG-CoA) reductase;

b) one or more gene(s) coding for steryl acyltransferase(s) in said cell are defective or deleted; and

c) said cell is prototrophic for histidine, leucine and uracil.

2. The cell according to claim 1 , wherein said cell is a cell of a stable cell line.

3. The cell according to claim 1 , wherein said cell is a genetically modified cell.

4. The cell according to claim 1 , wherein said cell is a Saccharomyces cerevisiae cell of the strain AH22.

5. The cell according to claim 1 , wherein the soluble HMG-CoA reductase is characterized in that

a) it is a truncated soluble HMG-CoA reductase protein lacking the membrane-binding region;

b) it is encoded on a vector under the transcriptional control of a promoter that is active in said cell; and/or

c) it is expressed under the control of a constitutive promoter.

6. The cell according to claim 1 , wherein the one or more gene(s) coding for steryl acyltransferase(s) are ARE1 and ARE2.

7. The cell according to claim 1 , wherein the terpene productivity of said cell is at least equivalent in comparison with the corresponding wildtype cell.

8. The cell according to claim 1 , wherein said cell produces reduced amounts of steryl acyl esters.

9. The cell according to claim 1 , wherein the terpene productivity of said cell is at least equivalent in comparison with the corresponding cell which is auxotrophic for at least one of histidine, leucine, or uracil.

10. A method of generating a modified yeast cell, said method comprising:

a) inserting a gene coding for soluble HMG-CoA reductase into a yeast cell;

b) selecting cells comprising a gene coding for said soluble HMG-CoA reductase;

c) deleting or mutating one or more gene(s) coding for steryl acyltransferase(s) of said cell;

d) converting said cell into a cell that is at least prototrophic for histidine, leucine and uracil, by means of

(i) inserting gene cassette(s) coding for one or more enzyme(s) for the production of histidine, leucine and/or uracil, and

(ii) revertant mutagenesis of one or more defective gene(s) coding for enzymes for the production of histidine, leucine or uracil, and

e) selecting cells that are prototrophic for histidine, leucine and uracil.

11. The method according to claim 10 , wherein said cell is derived from a Saccharomyces cerevisiae cell of the strain AH22.

12. The method according to claim 10 , wherein step a) comprises the insertion of a vector coding for soluble HMG-CoA reductase, wherein the expression of said soluble HMG-CoA reductase is under the control of a strong constitutive promoter active in said cell.

13. The method according to claim 10 , wherein the one or more gene(s) coding for steryl acyltransferase(s) are ARE1 and ARE2.

14. A method for the production of squalene, said method comprising:

a) cultivating the cells of claim 1 in a suitable culture medium; and

b) isolating squalene from the cells.

15. A method for the production of a pharmaceutical composition, said method comprising:

a) producing squalene by cultivating the cells of claim 1 in a suitable culture medium

b) isolating squalene from the cells, and

c) admixing squalene to said pharmaceutical composition.

16. The method according to claim 10 , wherein step d) is performed by revertant mutagenesis of a defective gene coding for an enzyme for the production of histidine and by inserting gene cassettes coding for enzymes for the production of leucine and uracil.