Immobilization of enzymes on polymeric microparticles

Abstract

As society becomes increasingly aware of environmental problems and their consequences, and looks for "greener" options, the necessity of those same alternatives to become viable to be used in large scale increases. The consequences of uncontrolled use of non-renewable resources such as fossil fuels and the implementation of non-sustainable politics are starting to become more and more visible and worrying, painting an uncertain and hostile future for the next generations. Taking this current scenario into account, the search for alternatives such as organic-based fuels created from biomass with low emissions has become increasingly more appealing, as a clean and sustainable solution to the high global energy demand. However, these alternatives still have high costs associated to their fabrication process, making them less competitive against conventional fuels. One of the main goals of the work developed in this dissertation is to determine the viability of using chitosan magnetic microspheres, activated with a glutaraldehyde solution, as an active support to use with enzymes like Viscozyme, in the hope that their magnetic properties allow for easier handling. This is achieved by studying the factors that influence the sphere's properties, optimizing their creation process and then immobilizing Viscozyme on their surface. Afterwards, the spheres are used in several hydrolysis reactions one after the other, in order to analyze their efficiency and operating stability. Results show that magnetic microspheres are as viable as non-magnetic ones in terms of production and size manipulation when using a coaxial airflow bead generator system. Both types of microspheres also show similar results in terms of surface activation with glutaraldehyde and immobilization of Viscozyme. Results obtained from HPLC are inconclusive in terms of yield difference between free enzyme and immobilized enzyme, but also show no clear difference in terms of viability between both types of microspheres.