ABSTRACT
Significant health benefits, including the prevention of cardiovascular diseases along with several physiological and cognitive disorders, are conferred by essential (ω-3, ω-6) fatty acids (EFAs). For ω-6 fatty acids, different whole grains, wheat germ, dried fruits and nuts including walnuts, almonds, pistachios, Brazil nuts and peanuts are good sources, while fish and seafoods have been the main source of ω-3 fatty acids. But problems such as overfishing and environmental pollution, along with the search for vegan sources, have increased the demand for alternative, novel and sustainable sources of these fatty acids. Microbes, especially marine microalgae, are comparatively rich in long-chain polyunsaturated fatty acids (LC-PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and are a promising alternative to fish and their oils. Genetic manipulation and extensive metabolic engineering of different plants and microorganisms producing LC ω-3 PUFAs are also established in sustaining EFA production. Meanwhile, fortification and enrichment of foods also remain attractive means to supply ω-3 PUFAs for human consumption and therapeutic purposes. This chapter reviews different conventional sources including plant, animal and microbial sources as well as the recent alternative approaches for essential fatty acid production.
