The present invention relates to an improved process for the specific production of poly-unsaturated
omega-3 and
omega-6 fatty acids and a process for the production of triglycerides having an increased content of unsaturated fatty acids, in particular
omega-3 and omega-6 fatty acids having at least two double bonds and a 20 or 22
carbon atom chain length. The invention relates to the produc-tion of a transgenic
organism, preferably a transgenic
plant or a transgenic
microorganism, hav-ing an increased content of fatty acids, oils or lipids containing C20- or C22- fatty acids with a
delta-5, 7, 8, 10
double bond, respectively due to the expression of a
delta-8-desaturase and a
delta-9- elon-gase from organisms such as plants preferably
Algae like
Isochrysis galbana or
Euglena gracilis. In addition the invention relates to a process for the production of poly unsaturated fatty acids such as Eicosapentaenoic, Arachidonic, Docosapentaenoic or
Docosahexaenoic acid through the co- expression of a delta -8-desaturase, a delta-9-
elongase and a delta-5 desaturase in organisms such as microorganisms or plants.The invention additionally relates to the use of specific
nucleic acid sequences encoding for the aforementioned proteins with delta-8-desaturase-, delta-9-
elongase- or delta-5-desaturase-activity,
nucleic acid constructs, vectors and organisms containing said
nucleic acid sequences. The invention further relates to unsaturated fatty acids and triglycerides having an increased content of at least 1 % by weight of unsaturated fatty acids and use thereof.