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

We reported previously on the function of acyl coenzyme A (acyl-CoA) oxidas e isozymes in the yeast Yarrowia lipolytica by investigating strains disrup ted 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 wer e studied for lactone production. Monodisrupted strains produced similar le vels 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 Delt a pox2 Delta pox3 double-disrupted strain, although slightly affected in gr owth, produced about 150 mg of lactone per Liter, indicating that Aox2p was not essential for the biotransformation, The Delta pox2 Delta pox3 Delta p ox5 triple-disrupted strain produced and consumed lactone very slowly. On t he contrary, the Delta pox2 Delta pox3 Delta pox4 Delta pox5 multidisrupted strain did not grow or biotransform methyl ricinoleate into gamma-decalact one, demonstrating that Aox4p is essential for the biotransformation.