Production of alpha-(R)-(E)-(+)-ionone in recombinant Saccharomyces cerevisiae

A method of producing enantiomerically pure (R)-(E)-(+)-alpha-ionone in Saccharomyces cervisiae comprising the steps of:

• (a) constructing recombinant yeast cells that overexpress native nucleic acids, or modified versions thereof, encoding at least one enzyme of the mevalonate pathway for synthesizing farnesyl pyrophosphate, wherein expression of the one or more enzymes is under control of constitutive or inducible promoters;
• (b) modifying the recombinant yeast cells from step (a) to further comprise heterologous nucleic acids that encode enzymes of an apocarotenoid pathway for synthesizing alpha-ionone, wherein said apocarotenoid pathway includes (i) an enzyme that condenses farnesyl pyrophosphate and isopentenyl pyrophosphate to form geranylgeranyl pyrophosphate, (ii) an enzyme that condenses two molecules of geranylgeranyl pyrophosphate to form phytoene, (iii) an enzyme that converts phytoene to lycopene, (iv) an enzyme that cyclizes lycopene to form δ-carotene and/or ε-carotene, and (v) an enzyme that cleaves δ-carotene and/or ε-carotene to produce alpha-ionone.