Metabolic engineering of the oleaginous yeast Yarrowia Lipolytica for the production of isoprenoids

Abstract

The oleaginous yeast Yarrowia lipolytica shows high potential as an isoprenoid platform. Considered a GRAS microorganism, it has a high cytosolic acetyl-CoA ux which is the main precursor of the Mevalonate pathway for the synthesis of isoprenoids. In this study we have engineered Y. lipolytica with the help of CRISPR/Cas9 to optimize the Mevalonate pathway in order to increase the production of the isoprenoids precursors. We have constructed several strains for the production of limonene (monoterpene), squalene (triterpene), 2,3-oxidosqualene (triterpene), valencene (sesquiterpene), -farnesene (sesquiterpene), ent-kaurine (diterpene) and - Carotene (tetraterpene). Biosynthesis was con rmed for all of them but only -farnesene, squalene and 2,3-oxidosqualene could be tested for production due to a lack of time. It was possible to prove that Yarrowia lipolytica can be used for the production of several isoprenoids. Improvement of the Mevalonate pathway has shown to have positive e ects in all tested production strains. We succeeded in cloning the di erent genes which encode for the speci c synthases for each product. We identi ed speci c changes in the precursor pathway of squalene and 2,3 oxidosqualene that are bene cial for its production. Obtained concentrations for squalene are competitive compared to the literature for Y. lipolytica.

El llevat oleagin os Yarrowia lipolytica mostra un gran potencial com a organisme plataforma per als isoprenoides. Considerat un organisme GRAS, t e un gran ux d'Acetil-CoA citoplasm atic el qual es el precursor principal de la ruta del Mevalonat per a la s ntesi d'isoprenoides. En aquest estudi hem fet enginyeria gen etica sobre Y. lipolytica amb l'ajuda de CRISPR/Cas9 per optimitzar la ruta del Mevalonat amb l'objectiu d'augmentar la producci o de precursors dels isoprenoides. Hem constru t diverses soques per a la producci o de limonina (monoterp e), esqual e (triterp e), 2,3-oxidoesqual e (triterp e), valencina (sesquiterp e), -farnes e (sesquiterp e), ent-kaurina (diterp e) i -Carot e (tetraterp e). La bios ntesi es va veri car per a totes les soques per o nom es el -farnes e, l'esqual e i el 2,3-oxidoesqual e varen poder ser testejats per a la producci o per falta de temps. Va ser possible provar que Yarrowia lipolytica pot ser empleat per a la producci o de diversos isoprenoides. L'optimitzaci o de la ruta del Mevalonat ha mostrat efectes positius en totes les soques testejades. Hem tingut exit en la clonaci o de diversos gens que codi quen per sintases espec ques per a cada producte. Hem identi cat canvis espec cs en la via metab olica del precursor de l'esqual e i el 2,3-oxidoesqual e que s on bene cioses per a la seva producci o. Les concentracions d'esqual e obtingudes s on competents si les comparem amb la literatura de Y. lipolytica.