Chapter 33 : Bioprospecting for Industrial Enzymes: Importance of Integrated Technology Platforms for Successful Biocatalyst Development

Abstract:

This chapter focuses on the discovery of enzymes from natural environments and on optimization of enzymes by protein engineering and directed molecular evolution to develop products that show optimal performance in their target application. Screening large numbers of culturable microbes is considered one of the most successful and efficient means of finding novel biological compounds such as biocatalysts, and this classical route of screening will continue to be applied with success in the future. Once the best performing candidates have been selected by primary and secondary screening, genes from the top candidates are cloned and expressed by a variety of different methods. Cloning and expression represent essential steps in the production of industrial enzymes today. Industrial applications utilizing enzymes as biocatalysts often put extreme demands on the properties of the enzymes due to the very harsh conditions often applied under such processes. Enzyme properties other than the protein stability-related parameters are important in a functional biocatalyst. There is no guarantee that the enzymatic answer to an industrial process can necessarily be isolated from nature, as such a guarantee would demand that survival of an organism would depend on an enzyme functional under the conditions relevant for that particular application. Two approaches for improving natural proteins in the laboratory have traditionally been taken, rational protein engineering and directed molecular evolution. Each of these two approaches is described separately; however, the borderline between the technologies has become less distinct in recent years.