Assistant Professor Frank Stewart has been awarded $571,000 to investigate how bacteria control interactions in methane and nitrogen cycles in the ocean. Specifically, this work will target bacteria in marine oxygen minimum zones, where the microbes convert nitrogen from a form that can be used by organisms to a gaseous form (N2) that can be lost from the ocean.

Recent studies, predominantly in freshwater environments, have discovered novel bacteria that link methane consumption to pathways of nitrogen loss. The Stewart lab has recently shown that such bacteria also occur in oxygen minimum zones. However, the contributions of these bacteria to ocean methane and nitrogen flux remain unknown. With the new funding, Stewart’s group will use a combination of genomics and biochemical measurements to characterize the metabolic potential and diversity of these bacteria in oxygen minimum zones and quantify their contribution to methane and nitrogen transformations. Meeting this goal is critical for constraining bulk fluxes of these chemicals in the open ocean and for predictive models of climate change, notably given the importance of methane as a potent greenhouse gas and the prediction that oxygen minimum zones will expand with global warming.

This project is also committed to enhancing knowledge of marine microbiology in the public arena and educational communities. Stewart and colleagues will incorporate results and concepts from this researchinto instructional modules for use in the Summer Workshop in Marine Science (SWiMS) at Georgia Tech (https://swimsgatech.wordpress.com/), an annual workshop to train middle and high school educators in marine science using lectures and lab exercises. This project will also involve training of local high school teachers through the Georgia Tech GIFT Program. Through the combined research and educational activities, this research will determine how low-oxygen conditions in the ocean regulate pelagic microbial diversity and methane cycling, as well as inform, engage, and excite scientific and general audiences about marine microbiology and biogeochemistry.