Production of cycloastragenol in metabolically engineered yeast.

Cycloastragenol is a bioactive, high-value triterpenoid derived from Astragalus membranaceus. Conventional plant-based extraction and chemical synthesis methods are expensive. To our knowledge, this is the first report on the de novo biosynthesis of cycloastragenol in yeast. The mevalonate pathway was reconstituted in yeast peroxisomes, and the engineered yeast produced 656.55 mg/L squalene. Further introduction of heterologous enzymes led the engineered yeast to produce 1.04 mg/L cycloastragenol, which demonstrated the yeast production of value-added medicinal molecules.