Influence of reactor configuration on the production of carvone from carveol by whole cells of Rhodococcus erythropolis DCL14

Abstract

Biocatalysis with whole cells in aqueous–organic systems is extremely attractive for conversion of substrates with low water solubility, specially if co-factor regeneration is required. However, in the latter case, cells should be able to stay viable, which makes both reactor configuration and operation conditions important.Three reactor configuration types were tested: mechanically stirred direct contact reactor, silicone tube membrane reactor and air-driven column reactor. All reactors were operated with pulse additions of carveol. The maximum trans-carveol conversion (92%) and specific production rate (1.69mg carvone/hmg prot) were obtained with the mechanically stirred reactor at, respectively, ambient temperature, in 50mM, pH 7.0 phosphate buffer, and at 28°C in mineral medium. The highest productivity (0.164mg carvone/hml org) was attained with the air-driven column reactor after the cells had been adapted to the presence of solvent, substrate and product.