Sustainable production strategies of omega-3 PUFAs and their enrichment in the human diet

With the continuing improvement of living standards, humans have been paying more attention to the influence of diet on their health and disease prevention. One group of the most important and essential foods are those rich in polyunsaturated fatty acids (PUFAs), in particular, ω-3 PUFAs. Beyond basic nutritional function, ω-3 PUFAs have been shown to have considerable beneficial effects on human growth and development as well as for the prevention and treatment of nonalcoholic fatty liver, autoimmune reactions, and various chronic illnesses. Although ω-3 PUFAs can be found in some terrestrial organisms, marine microorganisms, including bacteria, fungus-like organisms, and microalgae serve, as the richest natural source of ω-3 PUFAs. Through the food chain, ω-3 PUFAs can also be enriched in marine and freshwater organisms that are commonly consumed as part of the human diet (fish, crustaceans, mollusks, etc.). As the food consumption of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two representative essential ω-3 PUFAs, continues to grow, it is becoming increasingly crucial to develop efficient and sustainable systems toward production of these valuable fatty acids. This article summarizes the recent advancements in the biotechnological production of PUFAs, especially EPA and DHA, including strategies adopted to increase the production of ω-3 PUFAs and the development of some new microbial strains or plants able to produce DHA and EPA.