Coping With Toxicity

November 13, 2019

Plant and Microbial Biology faculty member Jannell Bazurto studies how a bacterium utilizes methanol, despite toxic intermediates. 

Jannell Bazurto

Plants emit oxygen. But that’s not the only chemical they send into the atmosphere. As it turns out, plants release a wide range of chemical compounds that attract pollinators, deter pests and support beneficial microbes.

Methanol is one of those chemical compounds and a unique microbe — Methylobacterium — uses methanol to grow. As Methylobacterium breakdown methanol for energy, they must cope with high levels of formaldehyde, a toxic intermediate. Formaldehyde destroys essential components of cells, reacting with DNA, proteins and cellular membranes. To cope with these stressors, Methylobacterium leverages a unique metabolism. Jannell Bazurto, an assistant professor in Plant and Microbial Biology, studies how their metabolic pathways work without harming the cell.

Methanol is a cost-effective, raw material that is frequently used in industrial processes, including biodiesel production. “Gaining a greater understanding of how Methylobacterium utilizes methanol, despite toxic intermediate compounds, has important implications for trying to exploit these pathways in industrial applications,” says Bazurto. 

For now, Bazurto’s lab is focused on understanding the cellular machinery and grows Methylobacterium in cultures. They feed different strains of methanol and study how they grow and cope with formaldehyde. Some strains can even thrive on the formaldehyde-only diet, but when switching between diets they can struggle to adjust. This transition mimics natural conditions. On a plant leaf, methanol spikes in the morning but then tapers off throughout the day. Because of this, Methylobacterium diets fluctuate throughout the day and so do their metabolisms. In order to compete with other microbes for resources, Methylobacterium must be able to readily take up methanol when it becomes available. Proteins that detect formaldehyde levels help Methylobacterium do this. 

Understanding these proteins and the trade-offs are important components of Methylobacterium metabolic processes. Soon Bazurto will study the bacterium on a plant host and examine its interactions.

“This system is very appealing as we can study it in culture and its native environment. By studying Methylobacterium in culture and on plants, we can best understand many quirks of basic cellular metabolism,” says Bazurto.

—Claire Wilson