FIG. 2.

Growth dependence of OLE1 KO on unsaturated fatty acids. (A) Growth rates of wild-type (WT), heterozygous (HET), homozygous (KO), and reconstituted (RE) mutant strains. Yeast cell growth was compared in YPD, YPDPO (YPD plus fatty acids), YNB, and YNBPO (YNB plus fatty acids) broth. The growth of the Candida cells was measured by cell density at OD₆₀₀. Experiments were repeated twice with four replicates for each medium, with similar results. (B) Spot growth assays of OLE1 KO and Fas2 KO on YPD supplemented with fatty acids or Tween 20, 40, or 80. A series of 10× dilutions of yeast cells were spotted onto agar. Plates were incubated at 30°C for 3 days, and images were digitally captured. Experiments were repeated twice with similar results. (C) The growth of the mutant yeast cells was dependent upon the amount of unsaturated fatty acids. Yeast cell strains were grown in YPD supplemented with 0 to 0.01% (wt/vol) palmitoleic acid (16:1), oleic (18:1) acid, or a mixture of these fatty acids. Yeast growth was determined by cell density after 24 h at 30°C with shaking. The results are the means from two independent experiments with triplicates. (D) A model of fatty acid biosynthesis generated from the assays. Fas is the Fas1 and Fas2 complex, which is required to synthesize SFA from malonyl-CoA. Ole1 is essential for UFA production from SFA precursors.