Over-expression of α-bisabolene by metabolic engineering of Yarrowia lipolytica employing a golden gate DNA assembly toolbox

Yarrowia lipolytica is a modern workhorse for biotechnology that is amenable to genetic manipulations and can produce high levels of various enzymes. The present study was designed to engineer Y. lipolytica for the overexpression of α-bisabolene, a valuable biofuel precursor and pharmaceutical, making use of this yeast's ability to accumulate lipids, and with the use of a golden gate DNA assembly (GG) toolbox. By transforming Y. lipolytica with a GG genetic construct involving truncated 3-hydroxy-3-methyl-glutaryle coenzyme A reductase (tHMG) and α-bisabolene synthase (Bis) genes controlled by the strong TEF promoter and Lip2 terminator, the engineered yeast was able to produce 489 mg l⁻¹ of α-bisabolene. This was increased to 816 mg l⁻¹ by transforming a lipid-over-accumulating Y. lipolytica strain with the same genetic construct. Higher production titers of up to 1243 mg l⁻¹ could be also achieved by varying the culture conditions of the transformed strains.