Fig. 3. (A) Resting cell assays of (+)-valencene hydroxylation to β-nootkanol and (+)-nootkatone using different constructs in S. cerevisiae. Hosts (CEN·PK2-1Ca, BY4741 and BJ5464), constructed based on backbone (YEplac181 and YEp352) and alcohol dehydrogenase isozymes (ADH1 and ADH3) were compared. (B) Changes of (+)-valencene oxidation capabilities in yeast PK2-32 when cells incubated over a period of 8 months. The total terpenoids was calculated as the sum of β-nootkanol and (+)-nootkatone in mg L⁻¹ ethyl acetate. Data is representative of triplicate determinations and error bars indicate standard deviations.