LABYRINTHULOMYCETE STRAINS FOR PRODUCING DOCOSAHEXAENOIC ACID
Improved labyrinthulomycetes strains that produce microbial oils having increased docosahexaenoic acid (DHA) content are disclosed. The strains have increased productivity with respect to a wild type strain. Also provided are microbial oil compositions having increased DHA content. Methods of improving strains for the production of lipid, such as DHA, are also included.
1 . A microbial oil comprising at least 25% of the total fatty acids as DHA and at least 6% of the total fatty acids as myristic acid.
2 . A microbial oil according to claim 1 , wherein the ratio of DHA to DPA is at least 3.5:1.
3 . A microbial oil according to claim 1 , wherein the ratio of DHA to DPA is at least 4:1.
4 . A microbial oil according to claim 3 , wherein at least 30% of the total fatty acids of the microbial oil are DHA.
5 . A microbial oil according to claim 4 , wherein at least 35% of the total fatty acids of the microbial oil are DHA.
6 . A microbial oil according to claim 1 , wherein 10% or less of the total fatty acids comprise DPA.
7 . A microbial oil according to claim 1 , wherein the total fatty acids comprise less than 2% ARA.
8 . A microbial oil according to claim 1 , wherein the total fatty acids comprise less than 1% EPA.
9 . A microbial oil according to claim 1 , wherein at least 10% of the fatty acids of the microbial oil are myristic acid.
10 . A microbial oil according to claim 9 , wherein at least 12% of the fatty acids of the microbial oil are myristic acid.
11 . A microbial oil according to claim 10 , wherein at least 15% of the fatty acids of the microbial oil are myristic acid.
12 . A product comprising a microbial oil according to claim 1 .
13 . A product according to claim 12 , wherein the product is a food product, an animal feed product, a cosmetic product, or a pharmaceutical product.
14 . A microbial oil according to claim 1 , wherein the microbial oil is isolated from a mutant microorganism.
15 . A mutant labyrinthulomycete microorganism that produces a microbial oil according to claim 1 .
16 . A mutant labyrinthulomycete microorganism that produces at least 25% of its fatty acids as DHA and at least 6% of its fatty acids as myristic acid.
17 . A mutant labyrinthulomycete microorganism according to claim 16 that produces at least 30% of its fatty acids as DHA and at least 10% of its fatty acids as myristic acid.
18 . A mutant labyrinthulomycete microorganism according to claim 16 , wherein the mutant microorganism produces DHA in a small scale culture at a rate of at least 100 mg/L/h, further wherein the mutant microorganism produces at least 20% more docosahexaenoic acid (DHA) and at least 100% more myristic acid as a percent of total fatty acids than the wild type strain from which it is derived.
19 . A mutant labyrinthulomycete microorganism according to claim 16 , wherein the total fatty acids produced by the microorganism comprise at least 30% DHA and at least 10% myristic acid.
20 . A mutant labyrinthulomycete microorganism according to claim 19 , comprising an 18S rDNA sequence having at least 98% identity to a sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, and SEQ ID NO:12.
21 . A mutant labyrinthulomycete microorganism according to claim 20 , wherein the mutant microorganism comprises an 18S rDNA sequence having at least 98% identity to:
a sequence selected from SEQ ID NO:5 and SEQ ID NO:9;
a sequence selected from SEQ ID NO:6 and SEQ ID NO:10;
a sequence selected from SEQ ID NO:7 and SEQ ID NO:11; and
a sequence selected from SEQ ID NO:8 and SEQ ID NO:12.
22 . A mutant labyrinthulomycete microorganism according to claim 21 , wherein the mutant microorganism comprises an 18S rDNA sequence having at least 98.5% identity to:
a sequence selected from SEQ ID NO:5 and SEQ ID NO:9;
a sequence selected from SEQ ID NO:6 and SEQ ID NO:10;
a sequence selected from SEQ ID NO:7 and SEQ ID NO:11; and
a sequence selected from SEQ ID NO:8 and SEQ ID NO:12.
23 . A mutant labyrinthulomycete microorganism according to claim 22 , wherein the microorganism is the strain deposited under NRRL number 50836, the strain deposited under NRRL number 50837, or a derivative of either.
24 . A microbial biomass comprising the mutant microorganism of claim 16 .
25 . A product comprising a microbial biomass according to claim 24 .