(66d) Biocatalytic Systems for Aromatic Oxidations

The purpose of this research is to engineer a biocatalytic system to facilitate the production of oxidation products in an economic and environmentally benign fashion. Oxygenases are powerful stereoselective and regioselective catalysts that are useful in the preparation of valuable pharmaceutical and specialty chemical intermediates. The need for cofactor regeneration necessitates the use of whole-cells in such bioprocesses. We have selected to work with various organisms carrying mono- and dioxygenases. Immobilization of these microorganisms, including solvent tolerant host organisms, will result in more stable biocatalysts that will be more amenable to meet process requirements. Specifically, retention of the immobilized catalyst will facilitate isolation of valuable products. This effort is critical to producing environmentally beneficial biotransformation systems by providing an environmentally benign oxidation process with reaction and separation of products. This work highlights some results comparing the effectiveness of naphthalene and toluene dioxygenases expressed in Escherichia coli for aromatic oxidations. The use of biphasic reaction media is used to increase productivity and enhance the reaction. We will show methods of creating an environmentally benign system.