Overproduction of α-Farnesene in by Farnesene Synthase Screening and Metabolic Engineering.

Maximizing the flux of farnesyl diphosphate (FPP) to farnesene biosynthesis is the main challenge of farnesene overproduction in . In this study, we screened α-farnesene synthase from soybean () with a higher catalytic ability. Combining the overexpression of the mevalonate (MVA) pathway with the expression of , an engineered yeast strain producing 190.5 mg/L α-farnesene was screened with poor growth. By decreasing the copies of 3-hydroxy-3-methylglutaryl-coenzyme (HMGR) overexpressed, the titer was increased to 417.8 mg/L. Then, the coexpression of and HMGR under the control of the GAL promoter and inactivation of lipid phosphate phosphatase encoded by promoted the titer to 1163.7 mg/L. The titer was further increased to 1477.2 mg/L at the shake flask level with better growth by the construction of a prototrophic strain. Finally, the highest α-farnesene production of 10.4 g/L in was obtained by fed-batch fermentation in a 5 L bioreactor.