Development of Biorefinery concepts via coumaric acid conversion into high-value compounds

• Grant number: 21/04254-3
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): December 01, 2021
• Effective date (End): November 30, 2023
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal researcher: Fábio Márcio Squina
• Grantee: Robson Tramontina
• Home Institution: Pró-Reitoria de Pós-Graduação, Pesquisa, Extensão e Inovação. Universidade de Sorocaba (UNISO). Sorocaba , SP, Brazil
• Associated research grant: 15/50590-4 - Lignin valorization in cellulosic ethanol plants: biocatalytic conversion via ferulic acid to high value chemicals, AP.BIOEN.TEM

Abstract

The 'biorefinery' concept emerges as an alternative for the sustainable production of fuels and chemicals from abundant plant biomass resources. These initiatives are beneficial not only to address global warming reduction, but also because they can promote economic opportunities and stimulate job growth. There are well-established methods for biomass pre-treatment and fractionation into cellulose, hemicellulose, lignin streams, and bio-conversion of cellulose and hemicellulose. Still, the lignin fraction is currently burnt as a fuel or used for low-value applications. Hence, there is considerable interest in lignin valorization to high-value chemicals, which is one of the major unsolved problems in the biorefinery concept. The hydroxycinnamic acids (i.e., p-coumaric acid - CA) extracted from lignocellulosic biomass represent potential aromatic building blocks that can be converted into several high-value products, with applications in the chemical and pharmaceutical fields. This project proposal will develop a biosynthetic route to produce Raspberry Ketone (RPK), a high-value molecule ($20,000/kg) used in the flavor industry, directly from CA from sugarcane bagasse. Adopting a fine-regulated biocatalytic strategy, this project will rely on biosynthetic principles by developing three genetic circuits (or "stacks") designed for E. coli chassis with the following objectives: (1) the lignocellulosic degradation module, consisting of arabinofuranosidase and esterase targeted for extracellular secretion, that enables the release of arabinose and CA from sugarcane bagasse; (2) the Sensing/Regulatory module, consisting of bacterial transcription factors and operons (i.e., araBAD and/or FerC), that activates metabolic pathways for efficient CA conversion by sensing the presence of arabinose (or CA) in the media; (3) biotransformation module, the pathway capable of converting CA into RPK, that mimics the raspberry's intrinsic route. Besides, to expand the possibilities of plant biomass valorization in the context of biorefineries, the current project will also contribute to developing an innovative strategy related to the development of these auto-regulated biotechnological stacks. These biotechnological stacks rely on molecular tools, such as plasmids, enzymes, bio-bricks, and cell strains, designed for direct one-pot conversion of other natural hydroxycinnamic acids into several high-value chemicals such as quercetin, vanillin, naringenin, and 4-vinyl-phenol. Accordingly, this study is of economic interest to the fine chemical industry that is constantly looking for innovation, sustainability, and natural ingredients. (AU)