De novo synthesis of trans-10, cis-12 conjugated linoleic acid in oleaginous yeast Yarrowia Lipolytica

BACKGROUND Conjugated linoleic acid (CLA) has many well-documented beneficial physiological effects. Due to the insufficient natural supply of CLA and low specificity of chemically produced CLA, an effective and isomer-specific production process is required for medicinal and nutritional purposes. RESULTS The linoleic acid isomerase gene from Propionibacterium acnes was expressed in Yarrowia lipolytica Polh. Codon usage optimization of the PAI and multi-copy integration significantly improved the expression level of PAI in Y. lipolytica. The percentage of trans-10, cis-12 CLA was six times higher in yeast carrying the codon-optimized gene than in yeast carrying the native gene. In combination with multi-copy integration, the production yield was raised to approximately 30-fold. The amount of trans-10, cis-12 CLA reached 5.9% of total fatty acid yield in transformed Y. lipolytica. CONCLUSIONS This is the first report of production of trans-10, cis-12 CLA by the oleaginous yeast Y. lipolytica, using glucose as the sole carbon source through expression of linoleic acid isomerase from Propionibacterium acnes.