Selective uptake of fatty acids by the yeast Yarrowia lipolytica

Yarrowia lipolytica, when cultivated on mixtures of free fatty acid substrates was found to remove C12:0, C14:0, Δ9C18:1, Δ9, 12C18:2 and Δ9, 12, 15C18:3 at significantly higher rates than C16:0 and C18:0, regardless of fatty acid composition of the initial substrate. C12:0, C14:0 and Δ9, 12, 15C18:3 were specifically and completely removed from the substrate, while Δ9C18:1 and Δ9, 12C18:2 concentrations decreased by 55‐80 wt‐% in comparison with initial concentrations. In contrast, concentration of C18:0 increased 2.1—3.5 fold in the substrate. Although C18:0 was removed slowly from the substrate, this fatty acid was selectively accumulated in the storage lipid. Inversely, only low quantities of Δ9C18:1 and Δ9, 12C18:2 and traces of C12:0, C14:0 and Δ9, 12, 15C18:3 were accumulated in the storage lipid. During storage lipid breakdown, cellular C16:0 and Δ9C18:1 were taken up more rapidly than C18:0. We concluded that the capability of Yarrowia lipolytica to selectively remove several fatty acids from the substrate and accumulate others could be used in modification of the composition of selected mixtures of fatty acids and probably of common fats, to produce “new” fats with a predetermined composition.