Field Samples: Understanding Microbes’ Role in Lake Ecosystems

Field Samples is a Q&A with aquatic researchers. Today  Robin Rohwer, a graduate student studying microbial ecology in Trina McMahon’s lab will give a public talk at noon on what microbes are in our lakes and what it is they do. It’s the Center for Limnology’s weekly Wednesday seminar

Robin on Lake Mendota. While it only takes a teaspoon of water to catch countless microbes, sometimes getting to that water is tough! Photo courtesy Robin Rohwer.
Robin on Lake Mendota. While it only takes a teaspoon of water to catch countless microbes, sometimes getting to that water is tough! Photo courtesy Robin Rohwer.

Who are you, where are you from, and how did you get here?
Rohwer and an undergraduate assistant take water samples during balmier months as well. Photo courtesy: Robin Rohwer.
Rohwer and an undergraduate assistant take water samples during balmier months as well. Photo courtesy: Robin Rohwer.

I’m a PhD student in the Environmental Chemistry and Technology Program. I’m in prof. Trina McMahon’s lab, where I study freshwater bacterial communities. My path to microbial ecology was winding. I studied biochemistry at Oberlin College, worked for a few years at a company developing dairy products, which is where I learned about next gen sequencing technology from a nutraceuticals trade magazine article talking about how probiotics were the fastest growing market share. As I read more about the the discoveries in the gut microbiome I started thinking about how metagenomics could be applied to the “black box” of microbial nutrient cycling in the environment. Turns out, lots of other people were thinking that too, so a bunch of applications later I ended up here, in the best lab to study it!
Why should someone not in the field of freshwater sciences care about your work?
It takes a team to study lakes! Rohwer's 2015 undergraduate sampling team pauses for a picture. Photo: Robin Rohwer.
It takes a team to study lakes! Rohwer’s 2015 undergraduate sampling team pauses for a picture. Photo: Robin Rohwer.

Microbes are major players in lakes, and many are beneficial. They impact global warming by cycling carbon between carbon dioxide and the even more potent green house gas methane. Some microbes produce the methane, but others consume it. Understanding the net effect requires understanding the whole community of microbes, which is what I study. For another example, microbes also impact water quality. Cyanobacteria can form toxic blooms, but their abundance is modulated by other microbes in the take. I study the entire community of microbes to understand how this interplay results in positive or negative environmental outcomes.

Stop by room 102 in the Water Science and Engineering Lab today at noon for the talk. Or follow updates at #cflseminar!