Akorede L. Seriki

Major: Biology

Faculty Advisor: Christopher J. Marx

Project Title:

Overcoming Formaldehyde Toxicity is Critical to Using Lignin-Derived Aromatics

Abstract

The need to shift towards renewable energy due to the depletion of fossil fuels has sparked interest in the utilization of lignin, a component of plant biomass, as a source of renewable energy. However, the generation of toxic single carbon (C1) byproducts during its upgrading into value-added compounds pose significant challenges to its effective degradation. The release of formaldehyde, a toxic compound, during the breakdown of methoxylated aromatics, impedes the sustainable utilization of lignin for energy.

We address the critical issue of formaldehyde toxicity in lignin valorization by investigating the metabolic stress response in the effective utilization of aromatics. To tackle this challenge, we adopt an innovative approach by employing Methylobacterium extorquens, an organism capable of preventing formaldehyde toxicity through the oxidation of C1 compounds like methanol.

Through metabolic engineering and experimental evolution, we enhanced the performance of our model system by introducing genes responsible for aromatics utilization. This study establishes, for the first time, a profound link between the formaldehyde stress response and the utilization of methoxylated aromatics. Furthermore, we demonstrate an improved cellular tolerance to these toxic compounds through mutagenesis, utilizing mutants in the C1 metabolism pathway.

By dynamically regulating the assimilation of C1 compounds and lignin aromatics utilization enzymes, we unveil a comprehensive system that enables the simultaneous assimilation of C1 compounds during lignin degradation. This innovative approach not only facilitates the production of biofuels but also promotes the proper handling of toxic compounds during lignin valorization.

This work paves the way for the efficient utilization of lignin as a renewable energy source. By elucidating the biological underpinnings of aromatics utilization and formaldehyde stress response, we provide valuable insights into overcoming the obstacles associated with lignin valorization. Ultimately, this study contributes to the development of a greener future by harnessing the full potential of lignin-derived aromatics.

Funding: Department of Energy (DOE)