Metabolism of ricinoleic acid into gamma-decalactone: beta-oxidation and long chain acyl intermediates of ricinoleic acid in the genus Sporidiobolus sp.

In order to study differences in gamma-decalactone production in yeast, fou r species of Sporidiobolus were cultivated with 5% of methyl ricinoleate as the lactone substrate. In vivo studies showed different time courses of in termediates of ricinoleic acid breakdown between the four species. In vitro studies of the beta-oxidation system were conducted with crude cell extrac ts of Sporidiobolus spp. and with ricinoleyl-CoA (RCoA) as substrate. The b eta-oxidation was detected by measuring acyl-CoA oxidase, 3-hydroxyacyl-CoA dehydrogenase activities, and acetyl-CoA production. The time courses of t he CoA esters resulting from RCoA breakdown by crude extract of Sporidiobol us spp. permit the proposal of different metabolic models in the yeast. The se models explained the differences observed during in vivo studies. (C) 20 00 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.