Inhibitory effects of substrate and product on the carvone biotransformation activity of Rhodococcus erythropolis.

Jenna L E Morrish, Andrew J Daugulis

Index: Biotechnol. Lett. 30(7) , 1245-50, (2008)

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Abstract

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.