Metabolism of ricinoleic acid into γ-decalactone: β-oxidation and long chain acyl intermediates of ricinoleic acid in the genusSporidiobolussp.

Abstract

In order to study differences in γ-decalactone production in yeast, four species of Sporidiobolus were cultivated with 5% of methyl ricinoleate as the lactone substrate. In vivo studies showed different time courses of intermediates of ricinoleic acid breakdown between the four species. In vitro studies of the β-oxidation system were conducted with crude cell extracts of Sporidiobolus spp. and with ricinoleyl-CoA (RCoA) as substrate. The β-oxidation was detected by measuring acyl-CoA oxidase, 3-hydroxyacyl-CoA dehydrogenase activities, and acetyl-CoA production. The time courses of the CoA esters resulting from RCoA breakdown by crude extract of Sporidiobolus spp. permit the proposal of different metabolic models in the yeast. These models explained the differences observed during in vivo studies.