Progress of metabolic engineering for the production of eicosapentaenoic acid

Eicosapentaenoic Acid (EPA) is an essential omega-3 polyunsaturated fatty acid for human health. Currently, high-quality EPA production is largely dependent on the extraction of fish oil, but this unsustainable approach cannot meet its rising market demand. Biotechnological approaches for EPA production from microorganisms have received increasing attention due to their suitability for large-scale production and independence of the seasonal or climate restrictions. This review summarizes recent research on different microorganisms capable of producing EPA, such as microalgae, bacteria, and fungi, and introduces the different EPA biosynthesis pathways. Notably, some novel engineering strategies have been applied to endow and improve the abilities of microorganisms to synthesize EPA, including the construction and optimization of the EPA biosynthesis pathway, an increase in the acetyl-CoA pool supply, the increase of NADPH and the inhibition of competing pathways. This review aims to provide an updated summary of EPA production.