Redesign and reconstruction of a steviol-biosynthetic pathway for enhanced production of steviol in Escherichia coli.

5'-UTR engineering, the fusion protein approach, and redox balancing improved the steviol titer in flask fermentation and bioreactor fermentation. The expression engineering of steviol-biosynthetic enzymes and the genome engineering described here can serve as the basis for producing terpenoids-including steviol glycosides and carotenoids-in microorganisms.