Fig. 2: A proposed metabolic pathway for alka(e)ne synthesis in Y. lipolytica.

a, b GC chromatograms from strain YLjbl-2-ΔFAA1 (red) and strain YLjbl-2 (blue) cultivated with exogenous palmitic acid-d₃₁ supplementation, respectively. Magenta and black lines represent the same cultivation without palmitic acid-d₃₁ addition. Two compounds with retention time of 7.26 and 8.36 min were found and identified to be pentadecane-d₃₁ and heptadecane-d₃₁, respectively. c GC chromatogram of products from the in vitro photocatalytic reaction using stearoyl-CoA lithium salt (≥90%, Sigma-Aldrich) as the substrate and purified CvFAP as the catalyst, showing that heptadecane could be synthesized from stearoyl-CoA. d Proposed mechanism for pentadecane-d₃₁ and heptadecane-d₃₁ formation from exogenous palmitic acid-d₃₁. Blue arrows indicate endogenous pathways while magenta arrows represent photodecarboxylation. e In vivo pentadecane-d₃₁ and heptadecane-d₃₁ formation rates resulting from the strain YLjbl-2 indicated that fatty acyl-CoA might be the preferred substrate for the photodecarboxylase. f, g Kinetic analyses of purified CvFAP at fixed concentrations for the determination of K_m and V_max when stearoyl-CoA lithium salt and lithium stearate (≥98.0%, TCI America) were used as substrates, respectively. Values of K_m and V_max were determined through Eadie-Hofstee plots. The results suggested that fatty acyl-CoAs were the preferred substrate for CvFAP over free fatty acids. h: A proposed pathway for alka(e)ne production catalyzed by CvFAP. Blue arrow represents photodecarboxylation and bold blue arrow indicates higher metabolic flux. ACC, acetyl-CoA carboxylase, FAS1 and FAS2, fatty acid synthase 1 and 2. Data represent mean value, n = 2 biologically independent samples. Source data underlying Fig. 2e–g are provided as a Source Data file.