Development of strategies for immobilization and co-immobilization of enzymes involved in biomass degradation

• Grant number: 19/22737-1
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2019
• End date: January 31, 2020
• Field of knowledge: Biological Sciences - Biochemistry - Enzymology
• Agreement: Fundação para a Ciência e a Tecnologia (FCT)
• Principal Investigator: Maria de Lourdes Teixeira de Moraes Polizeli
• Grantee: Ana Claudia Vici
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 18/07522-6 - Development of eco-friendly technologies for the hydrolysis of biomass and residues of cellulose pulp and paper industry, AP.R

Abstract

During the hydrolysis process of the biomass one of the critical points is the rapid degradation of the enzymes. Therefore, techniques to stabilize and reduce inactivation of enzymes, due to the distortion of their native structure by the influence of temperature, pH and organic solvents, are quite attractive. Immobilization of enzymes has been employed for this purpose, making the process less costly. This strategy is also an important tool to increase its bioactivity, allowing it to be reused. Immobilization is a method of fixing the enzyme to an immobilizing agent, and this method should be as smooth as possible, avoiding that the enzyme undergoes conformational change. The support of immobilization has an important role in maintaining the actual conformation and activity of the enzyme. Despite the great diversity of methods developed and applied in the immobilization of enzymes, there is no effective method for all of them, and works of immobilization of cellulases and xylanases for the hydrolysis of lignocellulosic biomass are scarce. Among the different methods, immobilization by covalent bonding and ion exchange has been widely employed by increasing the resistance of enzymes to high temperatures and denaturing solvents. The best-known immobilization techniques are: glyoxyl-agarose, MANAE-agarose, glutaraldehyde-chitosan, betwixt others. Therefore, in this project will be used substrates based on agarose, porous supports, carbon nanotubes and supports produced from the biomass itself. In this context, it will evaluate covalent and ion exchange immobilization techniques that result in an enzyme-immobilizing agent complex with good activity retention and high operational stability. Co-immobilization processes will also be evaluated to immobilize two or more enzymes. The evaluation of the different treatments and the capacity of the immobilization techniques will be performed by determining the immobilization efficiency, stability and bioactivity of the immobilized enzymes and co-immobilized in different chemical supports, as well as to evaluate the biocatalytic reusability. This project opens the perspective to develop new methodologies for the immobilization and co-immobilization of enzymes that aim at the degradation of different biomasses. In this work, it will have demonstrated methods for immobilization, using different material for support. According to each enzymes characteristic it will be followed different strategies for immobilization and co-immobilization.