Environmental Internship Program - 2022 Booklet

Lucy Huelskamp ’24
NEUROSCIENCE
CLIMATE AND
ENVIRONMENTAL SCIENCE
PROJECT TITLE
Molecular Biological
Investigation of the Marine
Nitrogen Cycle
ORGANIZATION(S)
The Ward Lab,
Department of
Geosciences,
Princeton University
LOCATION(S)
Princeton, New Jersey
MENTOR(S)
Bess Ward, William J.
Sinclair Professor of
Geosciences and the High
Meadows Environmental
Institute; Samantha
Fortin, Postdoctoral
Research Associate,
Geosciences; Amal
Jayakumar, Senior
Professional Specialist,
Geosciences
I researched genes involved in denitrification,
nitrogen fixation, nitrate reduction, and
nitrite oxidation — nosZ, nifH, nxrB, and
narG, respectively — as part of the Ward Lab,
which studies nitrogen cycling in oxygen
minimum zones (OMZs). I contributed to a
project studying nitrogen fixation in OMZs by
working to understand the diversity and activity
of the microbes involved. I amplified nifH, a
gene encoding dinitrogenase reductase, by
polymerase chain reaction (PCR) using barcoded
primer pairs from DNA and RNA extracted from
the eastern tropical North and South Pacific
OMZs’ water columns. After amplification, I
purified the PCR products using a gel extraction
protocol and quantified the clean products.
Equal quantities of these products will be pooled
and sequenced at the Genomics Core Facility.
The resulting sequence data is expected to
reveal the identities and relative abundances
of the dominant nitrogen-fixing microbes
present at different depths in the OMZs’ water
columns. This can be correlated with rate data
to offer insights into the diversity and activity
of prokaryotic nitrogen fixers present in these
OMZs. Through this project, I gained valuable
microbiology research experience through and
I enjoyed learning about the adaptations nitrite
oxidizing bacteria possess that allow them to
operate in OMZs.
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