Development of lignin-based epoxy supports for enzyme immobilization

• Grant number: 24/18357-7
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2025
• End date: August 31, 2028
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Anuj Kumar
• Grantee: Henrique César Pereira Coelho
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

The pulp and paper industry is expanding in Brazil. In 2024, investments of R$ 105 billion were announced until 2028 for the creation of new factories, expansion of existing facilities and logistical operations to flow production. Lignin, processed from wood pulping, is burned to supply energy, but there is interest from this sector for more noble applications. A possibility is the conversion of lignin to epoxy supports for enzyme immobilization by covalent bonds, but hydrophobic interactions between lignin and enzymes may result in protein denaturation, with immobilized enzymes showing lower activity compared to their free counterparts. Based on this problem, this PhD project proposes chemical modifications of kraft lignin, aiming to immobilize enzymes with the minimization of enzymatic activity loss. Modifications will include: 1) phenolation; 2.1) sulfomethylation or 2.2) aminomethylation; 3) epoxidation; and 4) partial cross-linking. Initial immobilization assays will be carried out with catalase and trypsin to verify the formation of covalent bonds between enzymes and supports . Subsequently, a detailed evaluation of these immobilized enzymes will be carried out to determine: 1) yields of immobilization and enzymatic activity; 2) kinetic parameters, Km and Vmax; 3) thermal inactivation; 4) enzymatic activity profile response to variations of temperature and pH; and 5) recyclability. The results of this project will contribute to both lignin valorization and development of new materials for enzyme immobilization.