Inhibitory effects of substrate and product on the carvone biotransformation activity of Rhodococcus erythropolis.
The aqueous substrate and product toxicity thresholds in the microbial biotransformation of (-)-trans-carveol to the fragrance/flavor compound (R)-(-)-carvone by Rhodococcus erythropolis were determined. Above aqueous phase concentrations of approx. 500 mg carveol/l and 200-600 mg carvone/l, the biotransformation activity of the biocatalyst was inhibited. This biotransformation was undertaken in a single aqueous phase 3 l [corrected] reactor in which a total of 5 ml carveol (mixture of isomers) was added before the biotransformation rate decreased significantly. The carvone volumetric productivity was 31 mg/lh. Although the growth of the organism post-exposure was not affected, dramatic morphological changes in response to the accumulation of the inhibitory substrate and product were observed.
Morrish
Jenna L E
JL
Department of Chemical Engineering, Queen's University, Kingston, ON, Canada, K7L 3N6.
Daugulis
Andrew J
AJ
D019149:Bioreactors / Q000382:microbiology; D001711:Biotransformation / Q000187:drug effects; D000081005:Cyclohexane Monoterpenes; D005421:Flavoring Agents / Q000378:metabolism*; D039821:Monoterpenes / Q000378:metabolism* / Q000494:pharmacology*; D012240:Rhodococcus / Q000254:growth & development*
D000081005:Cyclohexane Monoterpenes; D005421:Flavoring Agents; D039821:Monoterpenes; C006923:carvone; C075856:carveol