Metabolic engineering to produce sesquiterpenes in yeast.

[reaction: see text] Presented here is a metabolically engineered yeast strain that produces sesquiterpenes. Epi-cedrol synthase expressed in a native yeast strain converted endogenous farnesyl pyrophosphate to 90 microg/L epi-cedrol. This system was genetically modified to increase foreign terpene yields to 370 microg/L. The best yields were obtained by overexpressing a truncated 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in a upc2-1 mating type a background. This system allows sufficient production to characterize novel sesquiterpene synthase genes.