CAREER: Organic and inorganic carbon metabolism in methanotrophic bacteria.

Methanotrophic bacteria (methanotrophs) use methane as a source of carbon and energy; thus, play a critical role in Earth’s biogeochemical cycling of methane by either preventing its release to, or direct sequestration from, the atmosphere. These microbes have also garnered interest for biotechnology applications targeting conversion of methane to valuable products; and several studies support the feasibility of using methanotrophs to mitigate anthropogenic gas emissions and utilize natural gas and biogas methane for biomanufacturing.

However, a more complete understanding of the metabolism and physiology operating in these bacteria is required to understand their role in the environment and to develop biotechnologies for efficient methane capture and conversion. This project will advance the understanding of methanotroph metabolism and physiology to enable the development of carbon and energy-efficient, methanotroph-based biotechnologies.

This project will also foster scientific workforce development through advanced training of undergraduate and graduate students in basic and applied microbial sciences at the University of North Texas.

Evidence shows that the methanotroph Methylococcus capsulatus can uniquely co-utilize CH4 and CO2 as carbon sources, but the underlying metabolism and its regulation is incompletely understood. This project will leverage recently developed methanotroph genetic tools and high throughput CRISPR interference (CRISPRi) functional genetic techniques to further define the role of CO2 and the ribulose-1,5- bisphosphate carboxylase/oxygenase (RubisCO) in M. capsulatus metabolism and physiology.

These insights will guide the engineering of M. capsulatus biocatalysts for improved CH4 and CO2 conversion efficiency. These investigations will also provide a detailed systems understanding of an uncharacterized dual organic and inorganic carbon metabolism and its regulation that could be widespread in nature.

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.