Figure 4 . a) Oxidation of perillyl alcohol, nerol and farnesol to aldehyde and carboxylate forms. b) GC/MS extracted ion chromatograms (EIC) of aqueous phase sample of biotransformation of (ⅰ) perillyl alcohol, (ⅱ) nerol and (ⅲ) farnesol with BGA01(lower row) and its parent strain (upper row). BGA01 harbored the plasmid overexpressing CdGeDH and CdGaDH under the control of PT7. Peaks numbered on each EIC are identified as 1, perillyl alcohol; 2, perillic acid; 3, nerol; 4, nerolic acid; 5, geranic acid; 6 & 7, farnesol; 8, farnesal.