No Fish Required For Omega-3 Fatty Acid

Omega-3 fatty acids such as eicosapentaenoic acid (EPA) are popular health supplements. EPA used in supplements is commonly extracted from marine fish, but that source is limited and not sustainable in the long term. Quinn Zhu and coworkers at DuPont have engineered Yarrowia lipolytica, a so-called oleaginous yeast that easily accumulates lipids, to produce large amounts of EPA (Nat. Biotechnol. 2013, DOI: 10.1038/nbt.2622). The researchers chose a metabolic pathway in which the first step is rate-limiting, in order to minimize the accumulation of intermediates. The team added genes for four enzymes to convert linoleic acid to EPA. They further increased the yield by disrupting the activity of peroxisomes, which are organelles involved in breaking down long-chain fatty acids. The best of the engineered strains produced EPA at levels as high as 56.6% of total fatty acids and 15% of dry cell weight. Y. lipolytica could be similarly engineered to create strains that produce fatty acids and lipids for other products such as biodiesel.