Improvement of arachidonic acid and eicosapentaenoic acid production by increasing the copy number of the genes encoding fatty acid desaturase and elongase into Pichia pastoris.

ABSTRACT

Genes encoding Delta6 desaturase, Delta6 fatty acid elongase, and Delta5 desaturase from the alga, Phaeodactylum tricornutum, were co-expressed in Pichia pastoris to produce arachidonic acid (ARA; 204 Delta(5, 8, 11, 14)) and eicosapentaenoic acid (EPA; 205 Delta(5, 8, 11, 14, 17)). A panel of Pichia clones carrying progressively increasing copies of the heterologous gene expression cassette was created using an in vitro multimerization approach. ARA and EPA accumulated up to 0.3 and 0.1% of total fatty acids, respectively, in the recombinant P. pastoris carrying with double copies of these three heterologous genes, as compared to 0.1 and 0.05%, respectively, in the recombinant P. pastoris with single copy.