Involvement of acyl coenzyme A oxidase isozymes in biotransformation of methyl ricinoleate into γ-decalactone by Yarrowia lipolytica

We reported previously on the function of acyl coenzyme A (acyl-CoA) oxidase isozymes in the yeast Yarrowia lipolytica by investigating strains disrupted in one or several acyl-CoA oxidase-encoding genes (POX1 through POX5) (H. Wang et al., J. Bacteriol. 181:5140-5148, 1999), Here, these mutants were studied for lactone production. Monodisrupted strains produced similar levels of lactone as the wild-type strain (50 mg/liter) except for Delta pox3, which produced 220 mg of gamma-decalactone per liter after 24 h. The Delta pox2 Delta pox3 double-disrupted strain, although slightly affected in growth, produced about 150 mg of lactone per Liter, indicating that Aox2p was not essential for the biotransformation, The Delta pox2 Delta pox3 Delta pox5 triple-disrupted strain produced and consumed lactone very slowly. On the contrary, the Delta pox2 Delta pox3 Delta pox4 Delta pox5 multidisrupted strain did not grow or biotransform methyl ricinoleate into gamma-decalactone, demonstrating that Aox4p is essential for the biotransformation.