Functional and structural analysis of aryl-O-demethylases with potential for lignin valorization

• Grant number: 21/07139-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: January 01, 2022
• End date: March 03, 2026
• Field of knowledge: Biological Sciences - Biochemistry - Enzymology
• Principal Investigator: Priscila Oliveira de Giuseppe
• Grantee: Augusto Rodrigues Lima
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil
• Associated scholarship(s): 23/15383-4 - Biocatalytic demethylation of lignin-derived compounds investigated by ancestral reconstruction and characterization of Rieske non-heme iron enzymes, BE.EP.DD

Abstract

Lignin is a vegetable aromatic heteropolymer, which corresponds to about 30% of the organic carbon in our biosphere. It is considered one of the most promising renewable raw materials to serve as an alternative to petroleum in the production of chemicals, and thus reduce the greenhouse gas emissions associated with it. However, one of the main factors that hinder the use of lignin as a raw material for the production of chemicals is its structural heterogeneity, which imposes considerable technical challenges to arrive at high purity products. To try to overcome this bottleneck, an emerging strategy has been the study and Engineering of microorganisms capable of transforming complex mixtures of compounds derived from lignin into a specific metabolite of high added value, in a process known as biological funneling. One of the crucial steps in this process is the removal of methyl groups - present in abundance in lignin - by enzymes known as aryl-O-demethylases. Studies on the specificity of substrates and the molecular mechanisms of these enzymes are still scarce, which limits their rational design for applications aimed at enhancing lignin. In this context, our group identified in the genome of Xanthomonas axonopodis pv citri the presence of genes of aryl-O-demethylases that have not yet been characterized and that have low sequence identity with enzymes of known structure (34 to 41%). Thus, this project aims to determine the biological role of these enzymes in the bioconversion pathways of compounds derived from lignin, to investigate their substrate specificities and kinetic parameters, and to elucidate their structures by X-ray crystallography, in order to generate knowledge for the metabolic Engineering of microbial platforms for the conversion of lignin into high added-value chemicals. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARTIM, DAMARIS B.; BRILHANTE, ANNA J. V. C.; LIMA, AUGUSTO R.; PAIXAO, DOUGLAS A. A.; MARTINS-JUNIOR, JOAQUIM; KASHIWAGI, FERNANDA M.; WOLF, LUCIA D.; COSTA, MARIANY S.; MENEZES, FABRICIA F.; PRATA, RAFAELA; et al. Resolving the metabolism of monolignols and other lignin-related aromatic compounds in Xanthomonas citri. NATURE COMMUNICATIONS, v. 15, n. 1, p. 17-pg., 2024-09-12. (19/06921-7, 19/08590-8, 21/07139-0, 22/01070-1)