Investigation and rational engineering of molecular mechanisms for the bioconversion of aromatic compounds

Abstract

Aromatic compounds are widely used in several industrial sectors, but many are synthesized from petroleum derivatives, by processes of high energy demand that usually produce intermediates of high toxicity and hazardousness. In nature, there is a diversity of aromatic compounds, but they are often found in low concentration or contained in the polymeric structure of lignin, which makes their extraction and purification difficult in a sustainable and scalable way. In this context, biocatalysis and synthetic biology offer opportunities to overcome the challenges of sustainable production and transformation of aromatic compounds into other products, given the modularity, plasticity, scalability and low energy demand of biocatalytic processes. However, the development of new biotechnologies requires a solid knowledge base, which, in the field of bioconversion of aromatic compounds, is still very narrow and incipient. Although several enzymes active on aromatic compounds are known, and we are aware of some problems that they present, many of the mechanisms that govern their respective functions are poorly understood, which limits their improvement for industrial applications. Thus, we selected as a study model oxidoreductases and transferases representative of the main problems that can limit the efficiency of bioconversion of aromatic compounds: (i) low substrate specificity; (ii) reversibility of the reaction; (iii) low efficiency in vivo. Our main goal consists in unraveling the molecular mechanisms that contribute to these problems using a multidisciplinary approach that includes elements from four major areas of Biology (Structural, Molecular, Synthetic and Computational). As proof of concept, we intend to apply the knowledge generated in this project to the rational engineering of the selected enzymes and evaluate whether this approach would be effective in making them more efficient for being applied in microbial platforms dedicated to the bioconversion of aromatic compounds. (AU)