Design of a novel biocatalytic reactor for efficient conversion of aliphatic halogenated hydrocarbons

Halogenated hydrocarbons form one of the largest groups of industrially produced chemicals in the world today. As a result of their vast manufacture, significant quantities of these compounds are found present in the environment as contaminants. Classified by the EPA as “priority pollutants” because of their toxicity, carcinogenicity, and potential teratogenicity, many of these halogenated compounds have a severe impact on the natural surroundings. Clearly, the widespread production and use of these halogenated hydrocarbons necessitates the development of strategies to reduce and remediate this resultant environmental contamination,; While the use of biocatalytic technology in the production of bulk commodity chemicals is rare, there do exist a number of opportunities for biocatalysts to enhance the productivity of existing chemical processes via reduction of secondary waste by-products and/or more efficient raw material utilization. A microbial hydrolytic enzyme termed haloalkane dehalogenase has been identified and discovered to have the ability to catalyze the conversion of various halogenated alkanes to a corresponding alcohol. It is proposed that this hydrolytic dehalogenating enzyme can be integrated into a biocatalytic reactor and used in tandem with various existing epoxide processes as a method of reducing the amount of secondary haloalkanes produced. We have investigated the use of this haloalkane dehalogenase enzyme as a potential “natural” process solution to handling the significant volumes of these “man-made” wastes generated. Our work has sought to develop a biocatalytic reactor for the dehalogenation of these various waste, by-products and convert them into process viable intermediates, for further use in the epoxide synthesis. This research has focused on designing a bioreactor, which engineers around the perceived limitations involved with the incorporation of a biocatalyst for an industrial application as well as optimizes the reaction conditions such that the inherent advantages gained with a biological catalyst are fully realized. Additionally, we seek to produce a reactor, which also addresses the restrictions that arise because of the incompatibilities that subsist with the biological processing of hydrocarbons: limited solubilities and instability in an aqueous solvent. Various non-conventional reaction media are investigated for their use as reaction solvents, while the parameters associated with optimizing enzymatic activity and maximizing biocatalytic stability are explored.