An Integrated Model for Enzymatic Reactions in Reverse Micellar Systems: Nominal and Effective Substrate Concentrations

Abstract

The distribution of hexanol in a reversed micellar system of AOT/isooctane/buffer was quantitatively described by a model based on the volume fractions of micellar components and partition coefficients of the alcohol. A recombinant cutinase was used as a model biocatalyst since its activity is strongly dictated by the presence of short to medium alcohol chain lengths. It was assumed that hexanol would be accessed by cutinase if it is either in the water pool or in the surfactant layer (micellar) since the micelles are very small and resized upon protein microencapsulation. The integrated model takes into account the partitioning, the diffusion, and the adsorption of hexanol to AOT hydrocarbon tails and the effectiveness factors calculated to model the kinetic experiments. Thermostability data also support the model generated. Therefore, the model defines the reversed micelles composition in terms of hexanol concentration integrating the process globally.