De novo biosynthesis of bioactive isoflavonoids by engineered yeast cell factories

Isoflavonoids comprise a class of plant natural products with great nutraceutical, pharmaceutical and agricultural significance. Their low abundance in nature and structural complexity however hampers access to these phytochemicals through traditional crop-based manufacturing or chemical synthesis. Microbial bioproduction therefore represents an attractive alternative. Here, we engineer the metabolism of Saccharomyces cerevisiae to become a platform for efficient production of daidzein, a core chemical scaffold for isoflavonoid biosynthesis, and demonstrate its application towards producing bioactive glucosides from glucose, following the screening-reconstruction-application engineering framework. First, we rebuild daidzein biosynthesis in yeast and its production is then improved by 94-fold through screening biosynthetic enzymes, identifying rate-limiting steps, implementing dynamic control, engineering substrate trafficking and fine-tuning competing metabolic processes. The optimized strain produces up to 85.4 mg L-1 of daidzein and introducing plant glycosyltransferases in this strain results in production of bioactive puerarin (72.8 mg L-1) and daidzin (73.2 mg L-1). Our work provides a promising step towards developing synthetic yeast cell factories for de novo biosynthesis of value-added isoflavonoids and the multi-phased framework may be extended to engineer pathways of complex natural products in other microbial hosts. Isoflavonoids are a class of industrially important plant natural products, but their low abundance and structural complexity limits their availability. Here, the authors engineer Saccharomyces cerevisiae metabolism to become a platform for efficient production of daidzein which is core chemical scaffold for isoflavonoid biosynthesis, and show its application for production of bioactive glucosides from glucose.

Automated summary

Isoflavonoids are industrially important plant natural products, but their low abundance and structural complexity limit their availability. By engineering Saccharomyces cerevisiae metabolism to efficiently produce daidzein, a core chemical scaffold for isoflavonoid biosynthesis, researchers demonstrate its application for producing bioactive glucosides from glucose.