Production and Recovery of Limonene-1,2-Diol and Simultaneous Resolution of a Diastereomeric Mixture of Limonene-1,2-Epoxide with whole Cells of Rhodococcus Erythropolis DCL14

• Published in: Biocatalysis and biotransformation 2000, Vol.18 (3), p.223-235
• Main Authors: de Carvalho, Carla C.R., van Keulen, Frederik, Manuela, M., da Fonseca, R.
• Format: Article
• Language: English
• Subjects: Bioconversions. Hemisynthesis; Biological and medical sciences; Bioreactors; Biotechnology; Cells; Enzyme kinetics; Epoxide hydrolase; Fundamental and applied biological sciences. Psychology; Limonene epoxide; limonene epoxide hydrolase; Limonene-1,2-diol; limonene-1,2-epoxide; Methods. Procedures. Technologies; Organic solvents; Organic/aqueous system; Proteins; Rhodococcus erythropolis; Solubility; Substrates
• ISSN: 1024-2422; 1029-2446
• DOI: 10.3109/10242420009015246

Cells of Rhodococcus erythropolis DCL14 present a limonene epoxide hydrolase activity when grown on terpenes, which enables them to convert cis-limonene-1,2-epoxide to limonene-1, 2-diol. Trans-limonene-1,2-epoxide is only converted when no cis is present. An organic/aqueous system was developed to overcome the low solubility and instability of limonene-1,2-epoxide in the aqueous phase. The presence of the organic solvent allowed high epoxide concentrations to be used which resulted in high limonene-1,2-diol production rates. Relatively cheap solvents were tested without any significant loss of epoxide hydrolase activity. Using a 500 ml fed-batch mechanically stirred reactor it was possible to produce 197.2 g of diol per g of protein and to obtain a yield of 98.2% and 67.9% for the trans-epoxide and the diol, respectively. Production of 72.4 g of diol per g of protein was obtained using a magnetically stirred reactor with an external loop for product separation. In this case, trans-epoxide and diol yields were 98.5% and 94.1%, respectively. A downstream process, based both on the preference of the substrate for organic solvents and that of the product for the aqueous phase, allowed the recovery of limonene- 1,2-diol, as well as of the trans-epoxide, with a purity higher than 99%.