Microbial Adaptive Mechanisms to Iron Limitations Provides Clues to Early Life


Megan Brauner

UAA student battles cold, COVID-19 to understand life on Earth

Megan Brauner, a graduate student at UAA, has been working in the Kenai River estuary since 2019. Her project looks to Earth’s present to understand what may have happened in Earth’s past.

Brauner’s research focuses on how microbes store iron. All life requires iron for various metabolic processes and it’s one of the more abundant elements found in the universe. Not only do other planets (like Mercury) contain iron but Earth’s core itself is made of it.

Like any element iron is found more in some places than others. That is the same now as it was in the past. Unlike now, however, the Earth was not always rich in oxygen. As the Earth’s environment changed this forced microorganisms to evolve. As such, different microorganisms began to store iron differently which, in turn, contributed to the diversification of microbial species.

Her research took her to the Kenai where she took samples of estuary water during break up, in the middle of the summer, and while the region was frozen. Estuary environments mimic the transition from high to low iron, Brauner explained, and are model sites to understand the evolutionary mechanisms of microorganisms.

“I had to work through the ice and snow in order to get samples,” she said, “and it was so cold outside that the water was freezing while we were attempting to filter the microbes!”

Brauner expected iron concentrations to depend on salinity across the estuary. As a result of this, she anticipated seeing more iron storage in samples with a higher salinity. However, her expectations were dashed once she analyzed her findings; she was seeing a lack of iron storage in freshwater samples with no salinity. Yet, despite that, there was no significant change in iron concentration.

While Brauner has been keen to analyze her samples since spring, she was delayed.

“COVID-19 has unfortunately impacted my project,” Brauner said. “The university closed and for a few months I was unable to get into the lab.” COVID-19 also impacted the arrival of reagents - substances necessary for chemical analysis.

Brauner explained that thanks to her advisor (Dr. Brandon Briggs) and other UAA staff she was able to get back into the lab and get her project moving forward.

Doing research in Alaska under normal conditions can be a challenge, but doing so under the shadow of COVID-19 is anything but normal. Who would have thought digging through ice and snow for water samples from the Kenai estuary in winter would be the easy part?


Name: Megan Brauner, Graduate Student

Institution: University of Alaska Anchorage

Mentor: Brandon Briggs, bbriggs6@alaska.edu

Award: Research Grant

Funding Period: 2020 to 2021