Maximizing sclareol titers in AM238 cells. (A) EG60 and AM238 cells expressing CLS-ERG20 (F96C) only, CLS-ERG20 (F96C) with sclareol synthase SCLS, and CLS-ERG20 (F96C), SCLS with CD-HMG2. The engineered iterative perturbations generated a strain producing 12-fold higher sclareol levels than wild type cells; (B) Released NOH + FOH and GLOH + GGOH in EG60 and AM238 cells expressing the three plasmids. A reduction of released terpenols is seen in AM238 cells indicating a more efficient substrate conversion to sclareol; (C) Ergosterol and squalene levels in EG60 and AM238 cells expressing the three plasmids. Ergosterol levels are reduced by half in AM238 cells co-expressing SCLS and CD-HMG2, compared to CLS-ERG20 (F96C) only. Squalene levels are significantly increased by CD-HMG2 expression.