Peroxisomal beta-oxidation activities and gamma-decalactone production by the yeast Yarrowia lipolytica.
gamma-Decalactone is a peachy aroma compound resulting from the peroxisomal beta-oxidation of ricinoleic acid by yeasts. The expression levels of acyl-CoA oxidase (gene deletion) and 3-ketoacyl-CoA thiolase activities (gene amplification on replicative plasmids) were modified in the yeast Yarrowia lipolytica. The effects of these modifications on beta-oxidation were measured. Overexpression of thiolase activity did not have any effect on the overall beta-oxidation activity. The disruption of one of the acyl-CoA oxidase genes resulted in an enhanced activity. The enhancement led to an increase of overall beta-oxidation activity but reduced the gamma-decalactone production rates. This seemed to indicate a non-rate-limiting role for beta-oxidation in the biotransformation of ricinoleic acid to gamma-decalactone by the yeast Yarrowia lipolytica. All strains produced and then consumed gamma-decalactone. We checked the ability of the different strains to consume gamma-decalactone in a medium containing the lactone as sole carbon source. The consumption of the strain overexpressing acyl-CoA oxidase activity was higher than that of the wild-type strain. We concluded that peroxisomal beta-oxidation is certainly involved in gamma-decalactone catabolism by the yeast Y. lipolytica. The observed production rates probably depend on an equilibrium between production and consumption of the lactone.
Pagot
Y
Y
Ecole Nationale Supérieure de Biologie Appliquée à la Nutrition et l'Alimentation, Laboratoire de Biotechnologie, Dijon, France.
Le Clainche
A
A
Nicaud
J M
JM
Wache
Y
Y
Belin
J M
JM
D001711:Biotransformation / Q000502:physiology; D015152:Blotting, Northern; D007783:Lactones / Q000378:metabolism*; D008830:Microbodies / Q000378:metabolism*; D010084:Oxidation-Reduction; D012277:Ricinoleic Acids / Q000378:metabolism; D015003:Yeasts / Q000378:metabolism*
D007783:Lactones; D012277:Ricinoleic Acids; C030521:ricinoleic acid