Recombinant Microalgae Cells Producing Novel Oils
Disclosed herein are obligate heterotrophic microalgae cells containing an exogenous gene. In some embodiments the gene is a sucrose utilization gene, and further disclosed are methods of manufacturing triglyceride oils using sugar cane or sugar beets as a feedstock in a heterotrophic fermentation. In other embodiments the feedstock is depolymerized cellulosic material. Also disclosed are cells that produce medium chain fatty acids at levels not produced in non-recombinant cells of the same species and genus.
1 . An oil of a recombinant microalgal cell, the cell comprising an exogenous gene encoding a fatty acid desaturase or recombinant nucleic acids operable to reduce expression of a fatty acid desaturase so as to alter the proportion of unsaturated to saturated fatty acids in the oil.
2 . The oil of claim 1 , wherein the microalgal cell is of the family Chlorellaceae.
3 . The oil of claim 2 , wherein the microalgal cell is of the genus Chlorella.
4 . The oil of claim 2 , wherein the microalgal cell is of the genus Prototheca.
5 . The oil of claim 4 , wherein the microalgal cell is of the species Prototheca moriformis .
6 . The oil of claim 1 , wherein the cell comprises an exogenous gene encoding a fatty acid desaturase that is a stearoyl ACP desaturase.
7 . The oil of claim 1 , wherein the cell comprises an exogenous gene encoding a fatty acid desaturase that is an ω-6 fatty acid desaturase, ω-3 fatty acid desaturase, or ω-6-oleate desaturase.
8 . The oil of claim 1 , wherein the exogenous gene is in operable linkage with an inducible or repressible promoter.
9 . The oil of claim 8 , wherein the promoter is regulated in response to nitrogen levels.
10 . The oil of claim 1 , wherein the cell comprises exogenous nucleic acids operable to reduce expression of a stearoyl ACP desaturase.
11 . The oil of claim 1 , wherein the oil comprises fatty acids of altered chain length relative to a wild type microalgal cell due the expression of an exogenous acyl-ACP thioesterase.
12 . The oil of claim 11 , wherein the acyl-ACP thioesterase has hydrolysis activity toward one or more fatty acyl-ACP substrates of chain lengths C8, C10, C12, or C14.
13 . The oil of claim 11 , wherein the oil is increased in C8, C10, C12, or C14 fatty acids as a result of the expression of the acyl-ACP thioesterase.
14 . The oil of claim 13 , wherein the oil comprises 10% to 30% C8-C14 by dry cell weight.
15 . The oil of claim 13 , wherein the oil comprises 20% to 30% C8-C14 by dry cell weight.
16 . The oil of claim 13 , wherein the oil comprises at least 10% C8-C14 by dry cell weight.
17 . The oil of claim 16 , wherein the oil comprises at least 20% C8-C14 by dry cell weight.
18 . The oil of claim 17 , wherein the oil comprises at least 30% C8-C14 by dry cell weight.
19 . The oil of claim 13 , wherein the oil comprises at least 2% C12 by dry cell weight.
20 . The oil of claim 13 , wherein the oil comprises at least 4% C14 by dry cell weight.
21 . The oil of claim 13 , wherein the oil comprises at least 0.3% C8 by dry cell weight.
22 . The oil of claim 13 , wherein the oil comprises at least 2% C10 by dry cell weight.
23 . The oil of claim 13 , wherein the oil comprises over 30 area % C12-C14.
24 . The oil of claim 1 , wherein the oil comprises stigmasterol at a concentration of 40-60 milligrams per 100 grams of oil.
25 . The oil of claim 1 , wherein the cell comprises an exogenous gene encoding invertase and the cell uses sucrose to produce the oil.
26 . An oil produced by a recombinant microalgal cell, the cell comprising an exogenous gene encoding a fatty acid desaturase or a recombinant nucleic acid operable to reduce expression of a fatty acid desaturase so as to alter the proportion of unsaturated to saturated fatty acids in the oil.
27 . An oil produced by the process of cultivating a recombinant microalgal cell and extracting the oil, the cell comprising an exogenous gene encoding a fatty acid desaturase or a recombinant nucleic acid operable to reduce expression of a fatty acid desaturase so as to alter the proportion of unsaturated to saturated fatty acids in the oil.