Biotransformation of Limonene-1,2-epoxide to Limonene-1,2-diol by Rhodococcus erythropolis Cells An Introductory Approach to Selective Hydrolysis and Product Separation
Carla C. C. R. de Carvalho, Frederik van Keulen and M. Manuela R. da Fonseca*
Centro de Engenharia Biológica e Química, Instituto Superior Técnico, Av. Rovisco Pais, P-1049-001 Lisboa, Portugal
Article history:
Received July 7, 1999
Accepted April 3, 2000
Key words:
limonene epoxide hydrolase, cis and trans limonene-1,2-epoxide
Summary:
Cells of Rhodococcus erythropolis DCL14, when grown on terpenes, show a limonene epoxide hydrolase (LEH) activity which enables them to convert cis-limonene-1,2-epoxide to limonene-1,2-diol. The trans isomer is only converted when the cis isomer is not available. The transformation of limonene-1,2-epoxide ('limox') by whole cells of the above mentioned strain was used as a reaction model for the biotransformation of terpenes. The inclusion in the reaction system of an organic phase in which limox was dissolved led to high diol production rates. A diol production of m (diol)/m (protein)= 72.40 was achieved in a 500 mL mechanically stirred reactor with an external loop for product separation. A downstream process, based on the affinity of limox for the organic phase and that of the diol for the aqueous phase, was developed.
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