Undergraduate Researcher Discovers Unexpected Diversity In Key River Microorganisms
by Lacey Friedly - October 2nd 2023
Once a week for the past year, Kylee Brevick could be found at two particular spots on the Willamette and Columbia rivers, taking samples of water for testing. The undergraduate biochemistry major (and environmental science minor) was undertaking an independent research project with support from PSU's BUILD EXITO program, which helps students gain biomedical research experience and skills.
In the course of her project, Kylee discovered several different populations of an aquatic microorganism known as picophytoplankton. These have been well documented in lakes and oceans but not, until now, in rivers. The organisms, which perform photosynthesis and carbon fixation, are crucial in supporting aquatic life.
"We know a lot about these cells in lake systems and in the ocean. But we don't really know about their dynamics in river systems as much. And definitely not in the local river systems here," said Anne Thompson, principal investigator of PSU's Microbial Ecology Lab, where Kylee has a position as a BUILD EXITO Scholar.
Kylee's novel contribution to the body of knowledge about picophytoplankton is a significant achievement for an undergraduate, and could result in a scientific publication. She presented her work at the Portland State University Summer Research Symposium on September 21. For more details, see her research poster: Discovery of diverse freshwater picophytoplankton populations via flow cytometry.
WHY ARE THESE FINDINGS IMPORTANT?
"Phytoplankton do in water what plants do on land. So they capture the energy from the sun and convert that into biomass that feeds all kinds of animals. They also are responsible for transforming carbon from what's in the air to carbon that we can actually hold and touch. And if we think globally, phytoplankton do the most of that job on the earth. Since they have such a vital role, we really need to know their sensitivity. So how do they change? What's their genetic diversity? How does their function change when their ecosystem changes?" Thompson said.
Kylee documented several distinct populations of picophytoplankton in both the Willamette and the Columbia, and identified how each population serves slightly different functions, using different wavelengths of sunlight to drive nutrient cycles and carbon fixation.
HOW DID THE RESEARCH PROJECT WORK?
Kylee generated a unique dataset by taking weekly samples over the course of a year. She linked her data on the phytoplankton in the rivers systems to environmental data, which is provided for the public by the US Geological Survey (USGS).
"There are USGS stations that are constantly sampling both rivers, the Columbia and the Willamette. They collect mostly environmental data like temperature, turbidity, how fast the water is moving, and what kind of nutrients are present. Just all around environmental data that I can look at. And so I wanted to sample near those stations, so that it was relatively applicable," Kylee said.
Kylee, who designed the research project with Thompson's guidance, was particularly interested in seeing how the picophytoplankton react to changing conditions over time.
"We could have just taken a couple of samples from the river and seen that there are lots of different picophytoplankton types, and that would have been really exciting in itself. But what Kylee did was this persistent time course, and so she was able to show that they have different sensitivities. This could help us develop numeric models to really understand the system, and be able to predict how the system will change with for example, pollution or toxic cyanobacterial blooms or temperature changes—for example, Kylee sampled through a heat wave this summer. And she was really the driving force behind that commitment to the time series," said Thompson.
WHY SUPPORT UNDERGRADUATE RESEARCH?
The Research Symposium and BUILD EXITO are both programs of PSU's Center for Internship, Mentoring, and Research, or CIMR (pronounced "simmer"). CIMR's programs focus on diversifying and indigenizing the workforce in many fields such as health and medicine, STEM, and climate resilience. Shandee Dixon, who works for CIMR as a Research Learning Communities Coordinator, is in charge of placing students in research labs that match their interests.
"Authentic undergraduate research experiences do more than just teach students the mechanics of science; they empower scholars to think critically, collaborate seamlessly, and make meaningful contributions to their fields," Dixon said.
BUILD EXITO, which was funded by the National Institutes of Health (NIH), is in the process of sunsetting, but CIMR operates other grants and programs that achieve similar goals. For students like Kylee, this type of funding and support can make all the difference.
The support that students receive through CIMR provide them with crucial pathways, sharpening their professional skills and helping to determine the direction of their careers.
"Every research project is more than the aggregation of data; it's a testament to curiosity, dedication, resilience, and the joy of discovery," Dixon said.
[Quote from Kylee] "I was originally a part-time student, working full time. And ever since I got into the program, because of the funding, I've been able to transition to a full-time student. And not only am I getting funding, but I'm also getting experience that is relevant to what I want to do in my future career."
Kylee Brevick is a chemistry major who is interested in bridging the disciplines of chemistry, biology, and environmental science. Kylee's project addresses how populations of freshwater picocyanobacteria change over seasonal and spatial gradients in the Columbia River, the largest input of freshwater from North America to the North Pacific.
View the research poster