Investigating the metabolic cooperation between a phototrophic bacterium and a methanogenic archaeon

Washington University, Saint Louis MO

Investigators

Abstract

Methane is a powerful greenhouse gas and methanogenic archaea are important microbial contributors to biological methane production. Methane produced by some methanogenic archaea is facilitated by interactions with other microorganisms. The goal of this project is to use a model microbial community to better understand not only these interactions, but also how microbial organisms contribute to methane found in the environment. This project will be the inspiration for educational modules for undergraduate and high school students and for a workshop for local high school teachers. This project seeks to understand the metabolic cooperation or “syntrophy” between a phototrophic bacterium and a methanogenic archaeon to shed light on this interaction’s potential role in carbon and energy flow in anoxic (lacking oxygen) environments, and to develop it for light-dependent methane production. The research will investigate how this process influences the nitrogen cycle via nitrogen fixation. The work will test the hypothesis that phototrophs and methanogens interact in anoxic ecosystems and that this syntrophy can be harnessed for light-driven methanogenesis from CO2 and/or other waste organic carbon sources. Studying the syntrophy between a phototrophic bacterium and a methanogenic archaeon is important for two interconnected reasons. First, a detailed understanding of this growth strategy, co-metabolic activity, and interspecies electron transfer mechanisms would shed light on how these features contribute to carbon and electron flow in marine anoxic settings. Second, the studies will set the stage for creating and optimizing engineered communities for applications such as CO2 sequestration, and sustainable light-dependent bioproduction of methane. Anticipated scientific impacts will be to expand the fundamental understanding of both phototroph-methanogen interactions and light-driven methanogenesis from CO2 and organic carbon. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.