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

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.

Role of β-Oxidation Enzymes in γ-Decalactone Production by the Yeast Yarrowia lipolytica

“…Thus, 3-hydroxy-␥-decalactone is not exclusively a product of ␥-decalactone degradation. Y. lipolytica ␤-oxidation appears to follow established pathways (4), but at the C 10 level when the hydroxy group is at the ␥-carbon, there is competition between the next ␤-oxidation reaction and the hydrolysis of the CoA ester or lactonization (Fig. 1).…”

“…Flasks were shaken at 140 rpm for 18 h until the cultures reached the late logarithmic growth phase. Cells were harvested (10,000 ϫ g for 5 min), washed twice with phosphate buffer (50 mM, pH 7.4), and, for culture on methyl ricinoleate, resuspended in a 2-liter Setric reactor (NBS, Toulouse, France) containing the methyl ricinoleate medium (22) with 5 g of methyl ricinoleate per liter, 6.7 g of yeast nitrogen base per liter, and 5 g of NH 4 Cl per liter, emulsified by agitation in the presence of 0.2 g of Tween 80/liter. Agitation and aeration were at 300 rpm and 0.44 volume of air per volume of reactor per min, respectively.…”

Catabolism of hydroxyacids and biotechnological production of lactones by Yarrowia lipolytica

“…The compounds detected during the pathway were first those accumulating between two b-oxidation loops (Okui et al 1963a), excluding the 4-hydroxydecanoic acid which was probably lactonising spontaneously before detection, as reported for other 4-hydroxy acids (Fantin et al 2001). This very unstable acid was later detected (Feron et al 1996) and the detection of other intermediates was improved with the use of biphasic media or by processing the pathway in vitro (Blin-Perrin et al 2000).…”

“…Apart from rare and older studies mentioning acylCoA dehydrogenase activities (Haffner and Tressl 1996) or other characteristics that are specific to mitochondrial b-oxidation (Blin-Perrin et al 2000), this pathway is, in yeast, generally considered as being peroxisomal. bOxidation is a four-reaction sequence resulting in a twocarbon chain-shortening catalysed in peroxisomes by the following activities: acyl-CoA oxidase, 2-enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase and 3-ketoacyl-CoA thiolase (Fig.…”

“…The main topic in the strategies to improve the gdecalactone production yields concerns the b-oxidation pathway WachØ et al , 2000aWachØ et al , 2001Blin-Perrin et al 2000).…”