Accumulation of Neutral Lipids and β-Carotene by the Yarrowia lipolytica Yeast on a Medium with Sucrose as a Carbon Source

Recombinant Yarrowia lipolytica yeast has been used as a host strain for the expression of the Saccharomyces cerevisiae ScSUC2 gene and Y. lipolytica YlHXK1 gene encoding invertase and hexakinase, respectively. The expression was carried out on the background of the enhanced pathway of the synthesis of neutral lipids. This allowed the yeast to efficiently utilize glucose as a single carbon source. The engineered strain accumulated neutral lipids in amount of 50.7% of biomass dry weight, when cultured in tubes in minimal medium with nitrogen limitation and high sucrose content. The next metabolic engineering step was the use of the CRISPR-Cas9 editing system to introduce a heterologous β-carotene synthesis pathway by the expression of the Mucor circinelloides genes CarRP and CarB, encoding the bifunctional enzyme phytoene synthase/licopene-β-cyclase (carRP) and phytoene dehydrogenase (carB), as well as an increase in the expression level of the Y. lipolytica YlGGS1 gene, encoding geranyl diphosphate synthase enzyme. The β-carotene production on a sucrose-containing medium was shown for the first time; it amounted for 24.0 mg/g dry biomass, or 406.9 mg/L, on the 5th day of cultivation in tubes in a rich medium with a sucrose portioned supply (50 g/L). The corresponding values for a rich medium with a higher sucrose concentration (90 g/L) were 21.9 mg/g dry biomass and 625.8 mg/L. Yarrowia lipolytica, β-carotene, sucrose, CRISPR-Cas9 The plasmids pdKu70Yl-URA3, pLTet-SP-CAT, pARS-Cre-reverse, pMW-att-Cm and pGPD1Yl were kindly provided by Ph.D. I.A. Laptev ("Kurchatov Institute"-GOSNIIGENETIKA NRC). The work was carried out using the equipment of the Multipurpose Scientific Facility of the "Russian State Collection of Industrial Microorganisms" National Bio-Resource Center, NRC «Kurchatov Institute»-GOSNIIGENETIKA. The work was supported by state assignment no. 14 of 25.07.2012 AAAA-A20-120093090016-9. The quantitative analysis of lipids and β-carotene was carried out by V.A. Zolottsev within the framework of the "Long-Term Program of Fundamental Scientific Research in the Russian Federation (2021-2030)".