A Q&A with PhD Candidate Anna Bennett
By Reed Grumann 

Anna Bennett, a PhD candidate working in Trinity Hamilton’s lab, collects and studies photosynthetic bacteria that live in the extreme conditions found in Yellowstone’s hot springs. Bennett characterizes these cyanobacteria and their environment, providing data to inform evolutionary models of photosynthesis on Earth. 

How did you end up at the University of Minnesota?

At the time I began the application process for graduate school, I was working at an Air Force base in Ohio. I was researching synthetic biology with E. coli, and I knew that I wanted to get outside more, which is why I was looking into applying for environmental microbiology labs. I was accepted to study at the University of Cincinnati in the Hamilton Lab when she made the decision to move to the University of Minnesota. I decided to move too. I was really excited about her work with hot springs and extreme microbes, so it was the only lab that I interviewed with.

What stuck out to you about these extremophiles as compared to others?

I think it’s really interesting that these bacteria can perform photosynthesis. A lot of people only consider plants and a few types of algae when they think about photosynthesis, but these bacteria can do it, too. In fact, they were the first in Earth’s history to do it, but we still don’t know much about them.

Our basic question is “What did early organisms that performed photosynthesis look like?” I work to develop a better understanding of the physiology and ecology of their modern relatives to inform those evolutionary questions. 

What are the implications of your research?

The data we collect on the physiology and ecology of these cyanobacteria can be used to inform evolutionary models. To put it into broad terms, my results will help inform questions about the evolution of photosynthesis, and since photosynthesis led to oxygen on Earth, questions about the evolution of Earth as a whole. 

You work on the largest and smallest elements of biology—the environment and microbes. How do they complement each other?

Microbes are very important for large scale environmental cycles and tend to be important at the starting point of those cycles. Many of the microbes that we study fix carbon, which means they take carbon in a typically unusable form and make it usable. Since humans and animals are unable to do this for ourselves, we depend on the carbon that plants (and some microbes) fix. So microbes are critically essential for the rest of the environment. Without them we don’t have plants, we don’t have cows, and we don’t have us.

Reed Grumann is a writing intern in the Science Communications Lab, majoring in Microbiology and Political Science. He can be reached at gruma017@umn.edu