Development of a collection of extreme thermophilic enzymes active in the conversion of pet plastics

• Grant number: 22/14112-4
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: October 01, 2023
• Status: Discontinued
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Fábio Márcio Squina
• Grantee: Iara Ciancaglini
• Host Institution: Pró-Reitoria de Pós-Graduação, Pesquisa, Extensão e Inovação. Universidade de Sorocaba (UNISO). Sorocaba , SP, Brazil
• Associated research grant: 22/05731-2 - BEYOND: establishing a fungal cell factory for recombinant protein production, AP.TEM
• Associated scholarship(s): 24/10898-9 - Elucidating the Structure-Function Relationship in Novel PET-Degrading Enzymes, BE.EP.DD

Abstract

Petroleum-based plastics (PBP) have several applications, emphasizing the packaging market. The material of its composition is chemically inert and presents a high resistance to microbial degradation due to its structure. However, although these plastics provide infinite facilities to everyday life, they are now considered villains regarding their natural degradation. Thus, efforts have been made to find solutions to avoid accumulating this material in the environment. A recent study characterized a new species of bacteria, Ideonella sakaiensis 201-F6, capable of using polyethylene terephthalate (PET) as a carbon source through the action of two enzymes, PETase and MHETase, produced by it. Thus, this study brought feasible perspectives regarding the feasibility of the degradation and reuse of PBP by biotechnological processes. Research on active enzymes in PBP is in its infancy but advancing rapidly. Since 2011, studies have intensified on enzymes classified as esterases, lipases, cutinases, and carboxylesterases, but there are only about 60 publications describing the isolation and biochemical characterization of Active Plastic Enzymes (PAZymes). In this sense, the present project aims to contribute to the advancement in upcycling by developing a collection of thermophilic PAZymes produced in recombinant Escherichia coli. We aim to rescue different genes encoding enzymes for at least ten activities involved in the degradation of these polymers, following an order of priority: PETase, MHETase, polyurethanes, terephthalate dioxygenase, carboxylesterase, chitinase, cutinase, lipase, carboxymethylenebutenolidase, aryl acylamidase. This collection, in conjunction with comprehensive biochemical and biophysical studies, should assist in developing multienzyme systems with improved efficiency to PET and other PBP degradation. A collection of thermophilic PAZymes can be a powerful tool to drive advancement in the upcycling of these synthetic organic plastics, as the development of biotechnological processes depends on studies coordinated with other lines of research. Thus, the availability of a collection of enzymes with different activities involved in the degradation of PET and other PBP can constitute an important tool for developing the best synergies between physicochemical and biochemical processes, aiming at the sustainable management of petroleum-based plastics, as well as the production of advanced materials. (AU)