Novas estratégias à biorefinaria de lignocelulose aplicando a aldoketo redutase do cupim Coptotermes gestroi e enzimas redox associadas

Author(s)

Robson Tramontina

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2021-10-27

Examining board members

Fabio Marcio Squina; Igor Polikarpov; Luciana Gonzaga de Oliveira; Rafael Silva Rocha; Thiago Olitta Basso

• Advisor: Fabio Marcio Squina

Abstract

The termite species "Coptotermes gestroi" is a model of lignocellulose degradation on earth. This insect has several classes of enzymes that can be explored as new sources of catalysts for the valorization of lignocellulose, aiming for the sustainable production of value-added chemicals. Therefore, this work is focused on the biotechnological application of termite enzymes and related oxidative enzymes, in special an Aldo-keto reductase (CgAKR-1) that can be applied in lignocellulosic biorefineries. The first chapter of this thesis describes recent discoveries in the spotlight of termite biology. The CgAKR-1 was confirmed in C. gestroi digestomics playing a role in lignocellulose degradation. In this study, it was evidenced that fungal cellulolytic cocktails supplemented with CgAKR-1 showed higher yields in the saccharification of sugarcane bagasse. In addition, this enzyme also acted as a detoxifying agent against the phenolic aldehyde inhibitors found in lignocellulose hydrolysates. In the second chapter, we comprehensively developed a biocatalytic strategy for producing the versatile chemical building block, coniferol, directly from ferulic acid present in lignocellulosic biomass. This strategy was initially developed from a step of enzymatic hydrolysis, releasing ferulic acid from the lignocellulosic material by adding a feruloyl esterase (XynZ). Ferulic acid was double reduced to coniferol by an in vivo biocatalytic process using an E. coli strain, expressing the heterologous carboxylic acid reductase and CgAKR-1. This system represents a consolidated biodegradation-biotransformation strategy for producing high-value fine chemicals from waste plant biomass. Finally, in the third and fourth chapters, we describe a literature review and a research article contributing to the development of a novel enzymatic detoxification process and the application of this strategy for the optimization of fermentative processes. Therefore, CgAKR-1 and other redox enzymes present an excellent potential for the biorefineries of lignocellulosic material, both in processes that aim at a higher yield of enzymatic saccharification, fermentation, detoxification, as well as for the synthesis of high-value chemical building blocks from plant biomass (AU)

• FAPESP's process: 16/07926-4 - Novel integrative strategies through the aldoketo reductase from the termite Coptotermes gestroi for detoxification, saccharification and fermentation of lignocellulose aiming bioethanol production
• Grantee: Robson Tramontina
• Support Opportunities: Scholarships in Brazil - Doctorate