Development of bioreactors for application of biocatalysts in biotransformations and bioremediation*

Biotransformation systems, whether used for environmentally benign biocatalysis of synthetic reactions, or bioremediation of pollutants, require suitable biocatalysts and suitable bioreactor systems with particular characteristics. Our research focuses on the bioconversion of organic compounds, many of which are industrial residues, such as phenols, polyaromatic hydrocarbons, heterocyclic compounds, and polychlorinated biphenyls. The purpose of such biotransformations can be twofold: firstly, to remove them from effluents and convert them to less toxic forms, and secondly, to convert them into products with economic value. We conduct research in utilizing various isolated-enzyme and whole-cell biological agents; bioreactors, including novel membrane bioreactors, are used as a means of supporting/immobilizing, and hence applying, these biocatalysts in continuous systems. In addition, the enzyme systems are characterized biochemically, to provide information which is required in modification, adaptation, and scale-up of the bioreactors. The paper summarizes research on application of biofilms of fungal and bacterial cells and their enzymes, including hydrolases, polyphenol oxidase, peroxidase and laccase, in bioreactor systems including continuously operating membrane bioreactors.