Kelly Van Baalen ’19


Molecular Biology

Project Title

Investigating Alternative Nitrogen Fixation

Presentation Link

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I conducted research on alternative nitrogenases, which are enzymes responsible for converting atmospheric nitrogen into a form that organisms can use. Since nitrogen is essential for life, accurate measurements of the amount of nitrogen entering an ecosystem are critical to understanding the workings of that system. Canonical and alternative nitrogenases fix nitrogen at differing efficiencies. When there is a significant amount of alternative nitrogenase present in a system, knowing the proportion of alternative nitrogenase is essential to making accurate measurements of its nitrogen-fixing capacity. I worked to develop a new costeffective and precise method to determine this proportion. While working to build this method, I learned how to culture soil bacteria, perform assays to determine the rate of nitrogen fixation, use a gas chromatograph, and analyze experimental data. I was able to get an idea of what graduate research might be like and what kind of research I am interested in, while providing useful information to my lab.

* This internship is connected to the PEI Climate and Energy Grand Challenges project, “Controls on Alternative N2 Fixation: Consequences for Land Sequestration of Anthropogenic CO2 and Bio-hydrogen Production.”

Internship Year


Project Category

Climate and Oceans


Department of Geosciences, Princeton University


Xinning Zhang, Assistant Professor of Geosciences and the Princeton Environmental Institute; François Morel, Albert G. Blanke, Jr., Professor of Geosciences and the Princeton Environmental Institute