Construction Of Genetically Engineered Yarrowia Lipolytica To Produce Lycopene

As one of natural carotenoids, lycopene possesses great value in food and pharmaceutical industry due to its various physiological functions. Thus, utilizing synthetic biology techniques to construct genetically engineered microorganisms for lycopene production has recently become a hot point.Yarrowia lipolytica, considering its remarkable capacity for lipid biosynthesis and accumulation, is a prospective expression system for industrialized production of lipids. The objective of this research is to construct an engineered Yarrowia lipolytica to produce lycopene. So, we firstly constructed two plasmids pBIGgut2 and p BIGIntF, which contain crtB, crtI, GGS1, the key genes in lycopene biosynthetic pathway. The crtB, crtI and GGS1 gene encode phytoene synthase, phytopene desaturase and geranylgeranyl diphosphate synthase respectively, which catalyzes the synthesis of phytopene, lycopene, geranylgeranyl diphosphate accordingly. The plasmid pBIGgut2 and p BIGInt F can separately integrate their exogenous genes into the genome of Yarrowia lipolytica at GUT2 and IntF sites. The GUT2 gene is located in B chromosome and encodes glycerol-3-phosphate dehydrogenase which catalyzes the conversion of glycerol-3-phosphate to dihydroxyacetone phosphate, while the IntF DNA locates in F chromosome and is of none known functions. Then, plasmid pBIGgut2 was linearized and transformed into the genome of Yarrowia lipolytica 20362(Hmg) via lithium acetate method. After screening on minimal medium plates, nine positive transformants were obtained and among them, the highest yield of lycopene in flask fermentation is 49mg/l produced by LY3001-1 transformant. Finally, a preliminary research on the metabolic process of LY3001-1 strain was carried out in a 5L fermentor. Through fed-batch fermentation, the yield of lycopene reaches 492.5mg/L after 48 h.