Metabolic Engineering and Oil Supplementation of Physcomitrella patens for Activation of C22 Polyunsaturated Fatty Acid Production

Long chain (C C 20) polyunsaturated fatty acids (LC-PUFAs) represent important components of the human diet. Currently, the predominant sources of these fatty acids are marine fish and algal oils, but high production costs and diminishing feedstock, limit their supply and usage. A more regular sustainable source of these compounds is urgently required and therefore research is being conducted to develop a sustainable, land-based production system. This work describes the metabolic engineering of an artificial pathway that activates the production of C22PUFAs, docosatetraenoic acid or adrenic acid (ADA) and n-3 docosapentaenoic acid (DPA) in Physcomitrella patens using a gene from a marine algae Pavlova sp. encoding D-elongase and vegetable oil supplementation. The accumulation of ADA and x-3 DPA were dramatically increased to 24.3 and 11.7 mg L and accounted for 2.3 and 1.1% of total fatty acids, respectively. This is the first report on producing n-3 DPA, DHA precursor, in P. patens. The obtained results prove that this enzyme appears to be more active when fused to a green fluorescence protein reporter gene. These finding reveal that the modification of the fatty acid biosynthetic pathway by genetic manipulation and nutritional supplementation, to produce specific PUFAs in a non-seed lower plant, is a promising technique.