Reprogramming the fatty acid metabolism of Yarrowia lipolytica to produce the customized omega-6 polyunsaturated fatty acids

Omega-6 polyunsaturated fatty acids (ω6-PUFAs), such as γ-linolenic acid (GLA), dihomo-γ-linolenic acid (DGLA) and arachidonic acid (ARA), are indispensable nutrients for human health. Harnessing the lipogenesis pathway of Yarrowia lipolytica creates a potential platform for producing customized ω6-PUFAs. This study explored the optimal biosynthetic pathways for customized production of ω6-PUFAs in Y. lipolytica via either the Δ6 pathway from Mortierella alpina or the Δ8 pathway from Isochrysis galbana. Subsequently, the proportion of ω6-PUFAs in total fatty acids (TFAs) was effectively increased by bolstering the provision of precursors for fatty acid biosynthesis and carriers for fatty acid desaturation, as well as preventing fatty acid degradation. Finally, the proportions of GLA, DGLA and ARA synthesized by customized strains accounted for 22.58%, 46.65% and 11.30% of TFAs, and the corresponding titers reached 386.59, 832.00 and 191.76 mg/L in shake-flask fermentation, respectively. This work provides valuable insights into the production of functional ω6-PUFAs.