Publications

Optimization of Biocatalytic function of hydrolases entrapped in tailored sol-gel materials

Ursoiu, A.; Ungurean, M.; Todea, A.; Boeriu, C.G.

Summary

The rational design of novel and more efficient biocatalysts emerged as a major research objective of industrial biotechnology in the last decades. Besides several important developments concerning engineered and de novo designed enzymes, immobilization has been proved as a key issue to increase the efficiency of biocatalytic processes and meet the requirements of manufacturing large-scale or specialty products. Sol–gel entrapment showed a tremendous evolution as a generic method for immobilization of biomolecules. The multiple possibilities to fine-tune the physico-chemical properties of the matrix allowed the confinement of a large variety of enzymes and preparation of robust solid-phase biocatalysts, with long-term stability and suitable for repeated use. In this work, we present an overview of the methods developed by our research group for tailoring the sol–gel entrapment of several hydrolases in hybrid organic–inorganic matrices, to ensure improved stability and unaltered catalytic function. The main accomplishments in optimization of immobilization procedure and parameters for Candida antarctica B lipase, Subtilisin, Celluclast cellulase and ß-galactosidase, as well as the results of utilization of these novel biocatalysts in hydrolysis, regio- and enantioselective synthesis of bioproducts with high industrial capability will be highlighted. Usually, ternary silane precursor systems allowed better possibilities to set up the appropriate structure for every sol–gel matrix in terms of hydrophobicity, porous structure, or presence of specific functional groups, based on the characteristics of the enzyme subjected to immobilization and the designed application. Utilization of ionic liquids as additives was beneficial particularly for lipases, improving the catalytic efficiency