Fig. 4

Xylose-enabled yeast strains expressing EaDAcT produce acetyl-TAGs. a ESI mass spectra of neutral lipid extracts from xylose-enabled yeast strains where known enzymes for TAG biosynthesis were knocked out and EaDAcT expressed after growth on YPD medium for 18 h. Acetyl-TAGs are highlighted in purple and lcTAGs in orange. Signal peaks possess the m/z value of the [M + NH₄]⁺ adduct. For clarity, only the number of acyl carbons and not the number of double bonds (x) in each series of TAG molecular species is indicated. Tritridecanoin (tri13:0) is used as an ESI–MS external standard and tripentadecanoin (tri15:0) was added as an internal standard during lipid extraction. Quantification of lcTAG and acetyl-TAG content of different xylose-enabled yeast strains after 18 h (b) and 48 h (c) growth on YPD medium. Strains were either capable of normal lcTAG biosynthesis (WT) or possessed mutations in key biosynthetic genes (4KO) and had either EaDAcT or control sequence integrated. Values represent the mean ± SD of acetyl-TAG or lcTAG content derived from four different ESI–MS analyses and are representative of at least two replicate cultures