Optimization of Yarrowia lipolytica’s β-oxidation pathway for γ-decalactone production

Abstract

The yeast Yarrowia lipolytica growing on methyl ricinoleate produces various lactones, ␥-decalactone, the worthy aroma compound, 3-hydroxy-␥-decalactone without sensorial properties and two decenolides of various interest. Unfortunately, these three latter lactones are produced at high levels by this yeast, decreasing yields and complicating the extraction of ␥-decalactone. In this study, the production of ␥-decalactone was increased through a genetic engineering of the strain and the accumulation of the three other lactones was lowered. Theses results show that it is possible to improve the mastering of the complex ␤-oxidation pathway (the metabolic pathway involved in these bioconversions) by playing on genetic factors.

Genetic engineering of the β-oxidation pathway in the yeast Yarrowia lipolytica to increase the production of aroma compounds

“…3) is very comparable showing without doubt the capacity of this strain to degrade ␥-decalactone contrasting with the results obtained with the previous pox3 pox4 pox5 construction [14]. A possible explanation for these different results is that the previous construction grew very slowly whereas the new one grows at a rate similar to that of the wild type.…”

“…The deletion of pox5 decreased activity on the complete chain-length spectrum whereas the deletion of pox4 exhibited no significant effect. To confirm the activity or inactivity of these enzymes, a construction was made involving the deletion of several acyl-CoA oxidase encoding genes ( pox2 pox3 pox5) and a multicopy insertion of POX2, the long-chain specific encoding gene [14] but, as the efficiency of the multicopy insertion was low, the constructed strain exhibited an altered growth resulting in a low production and no degradation of ␥-decalactone but whether the absence of detectable degradation was due to a lack of short-chain active acyl-CoA oxidases or to a rate of degradation lower than the rate of production was not determined. As the growth rate of mutant strains is very important for industrial application and as this parameter is linked to the number of deletion of genes coding for lipid-degradation-enzymes, it is of fundamental interest to establish the role of each of these enzymes.…”

Catabolism of hydroxyacids and biotechnological production of lactones by Yarrowia lipolytica

“…By disrupting the corresponding genes (pox4, pox5), one takes the risk of constructing a strain which is not very active, as the only active Aox remaining would be Aox2. We therefore constructed a strain disrupted for pox2, pox3 and pox5 (which still possesses POX4, encoding a weakly active Aox) and with POX2 reincorporated in multicopies (WachØ et al 2002). The metabolism of this strain was slow, but no lactone degradation was observed.…”

Biotechnology for the production of essential oils, flavours and volatile isolates. A review.

“…[283] Yarrowia lipolytica with genetically engineered genes of the b-oxidation genes is able to reach 10 g/l g-decalactone production from ricinoleic acid esters. [285][286][287][288][289] Volatile dicarboxylic acids can accumulate at amounts up to 80 g/l, when various yeasts having genetically interrupted b-oxidation and amplified w-hydroxylation were fed with fatty acids and alkanes.…”

“…Deleted acyl-CoA oxidases, selective for short chain fatty acids 10-Fold increase in g-decalactone production from fatty acids [287,288,289] Various yeasts (Candida, Saccharomyces, Schizosachcaromyces, Pichia, Yarrowia,…”