Long chain omega-3 and omega-6 polyunsaturated fatty acid biosynthesis by expression of acyl-CoA lysophospholipid acyltransferases

1. A recombinant oleaginous microbial host cell for improved production of at least one long-chain polyunsaturated fatty acid, said host cell comprising at least one isolated polynucleotide encoding a polypeptide having at least acyl-CoA:lysophospholipid acyltransferase activity, wherein the polypeptide comprises (i) at least 90% amino acid identity, based on the Clustal W method of alignment, compared to the amino acid sequence of SEQ ID NO:11, and (ii) at least one membrane bound O-acyltransferase protein family motif selected from the group consisting of: SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5 and SEQ ID NO:28;

wherein the isolated polynucleotide is operably linked to at least one regulatory sequence, and further wherein the host cell has at least one improvement selected from the group consisting of:

(i) an increase in C 18 to C 20 elongation conversion efficiency compared to a control host cell, and

(ii) an increase in delta-4 desaturation conversion efficiency compared to a control host cell.

2. The recombinant host cell of claim 1 , wherein the at least one long-chain polyunsaturated fatty acid is selected from the group consisting of: eicosadienoic acid, dihomo-gamma-linolenic acid, arachidonic acid, eicosatrienoic acid, eicosatetraenoic acid, eicosapentaenoic acid, docosatetraenoic acid, omega-6 docosapentaenoic acid, omega-3 docosapentaenoic acid and docosahexaenoic acid.

3. The recombinant host cell of claim 1 , wherein the isolated polynucleotide is stably integrated in the host cell; and

further wherein the improvement is selected from the group consisting of:

a) an increase in C 18 to C 20 elongation conversion efficiency of at least 4% compared to a control host cell; and

b) an increase in delta-4 desaturation conversion efficiency of at least 5% compared to a control host cell.

4. The recombinant host cell of claim 3 , wherein the improvement is selected from the group consisting of:

a) an increase in C 18 to C 20 elongation conversion efficiency of at least 13% compared to a control host cell, wherein the recombinant host cell produces eicosapentaenoic acid;

b) an increase in C 18 to C 20 elongation conversion efficiency of at least 4% compared to a control host cell, wherein the recombinant host cell produces docosahexaenoic acid;

c) an increase in delta-4 desaturation conversion efficiency of at least 18% compared to a control host cell, wherein the recombinant host cell produces docosahexaenoic acid;

d) an increase of at least 9% of eicosapentaenoic acid measured as a weight percent of the total fatty acids compared to a control host cell;

e) an increase of at least 2% of eicosapentaenoic acid measured as a weight percent of the total fatty acids compared to a control host cell, wherein the recombinant host cell produces docosahexaenoic acid; and

f) an increase of at least 9% of docosahexaenoic acid measured as a weight percent of the total fatty acids compared to a control host cell.

5. The recombinant host cell of claim 1 , wherein the host cell is a yeast.

6. The recombinant host cell of claim 5 , wherein the yeast is Yarrowia lipolytica.

7. The recombinant host cell of claim 1 , wherein the polypeptide comprises at least 95% amino acid identity compared to the amino acid sequence of SEQ ID NO:11.

8. The recombinant host cell of claim 1 , wherein the regulatory sequence comprises a heterologous promoter.

9. A method for making an oil comprising eicosapentaenoic acid and/or docosahexaenoic acid comprising:

a) culturing the recombinant host cell of claim 1 , wherein an oil comprising eicosapentaenoic acid and/or docosahexaenoic acid is produced; and

b) optionally recovering the oil of step (a).

10. The method of claim 9 , wherein the recovered oil of step (b) is further processed.

11. The method of claim 9 , wherein the host cell is an oleaginous yeast.

12. The method of claim 11 , wherein the oleaginous yeast is Yarrowia lipolytica.