Overexpression of diacylglycerol acetyltransferase from Euonymus europaeus in Yarrowia lipolytica leads to the production of single-cell oil enriched with 3-acetyl-1,2-diacylglycerols.

The 3-acetyl-1,2-diacylglycerols (acTAG) are the molecules that are structurally similar to triacylglycerols (TAG). They are naturally produced by plants of the family Celastraceae and animals such as Cervus nippon and Eurosta solidaginis. The presence of acetate in the sn-3 position of the glycerol backbone confers advantages to these compounds, e.g., lower viscosity and calorific value compared to classical TAG. In this work, the gene EeDAcT, which encodes diacylglycerol acetyltransferase in a species of bush (Euonymus europaeus), was overexpressed in strains Po1d (capable of accumulating storage lipids) and JMY1877 (incapable of accumulating storage lipids) of Yarrowia lipolytica, to test the activity of the gene EeDAcT and the production of acTAG in oleaginous and non-oleaginous genetic backgrounds. It was observed that both the strains containing the gene EeDAcT (YL33 and YL35 for Po1d and JMY1877 strains, respectively) produced acTAG. The strain YL33 accumulated up to 20% intracellular lipids, 20% of which was acTAG and 40% was TAG. On the other hand, the strain YL35, that showed interrupted TAG accumulation, produced up to 10% acTAG as the only storage lipid. Unfortunately, the quantity of acTAG produced in YL35 was insignificant, as the overall lipid accumulated in the strain was not more than 4% of the biomass. The fatty acid profile of acTAG produced by the YL33 strain was remarkably similar to TAG, and both of these structures were rich in oleic (45%) and palmitic (25%) acids.