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Modern-Day Explorer

Why would UT microbiologist Karen Lloyd descend into the crater of an active volcano?

December 10, 2018

The answer is simple, as far as Lloyd is concerned. “I would like to know how all of life interconnects.”

She believes the key will be found in microbes living in extreme environments and deep beneath the earth’s surface.

In Costa Rica, Karen Lloyd and a group of international scientists from the Deep Carbon Observatory investigate life in extreme environments.

An associate professor of microbiology, Lloyd has been traveling the globe in search of clues. Her recent work has been carried out with a group of scientists who are part of the Deep Carbon Observatory, a global community that investigates how carbon is distributed on and inside the earth.

The group traveled to Costa Rica, where they descended into the crater of the Poás Volcano and collected samples from a lake that is pure acid.

Left: Donato Giovannelli, a microbiologist with Rutgers university, and Karen Lloyd, pose for a photo before descending into the Poás Volcano crater. Top right: Giovannelli and Lloyd take samples from a crater lake. Bottom right: A team of scientists, project members, and videographers pause during the climb out of the crater.

“Costa Rica is a subduction zone, where the oceanic plate is getting shoved underneath the continental plate. That creates a different chemical and physical environment for the microbes,” she explains. “Ideally, we’d really like to find the microbes that are living deep in the earth and getting expelled when the water rushes past them.”

By taking samples in volcanic areas, Lloyd is trying to find out if microbes can survive subduction, and if those microbes can influence the chemistry of the earth’s surface.

Crystals of elemental sulfur forming in a fumarole inside the Poás Volcano crater.

“We know, for example, that underground microbes rival the total number of microbes on the surface of the earth,” Lloyd says, referring to a 2018 report she co-authored for the Deep Carbon Observatory. “But how do they survive in these extreme volcanic environments? What are their goals in life? What kind of food do they eat? How do they get their energy? And perhaps most importantly, what is their impact on us?”

As she investigates these questions, Lloyd takes students into the field with her.

“It’s crucial to me that they make these projects theirs,” she says. “I am just here to help them navigate the data and the methods.”

One of her microbiology PhD students, Kate Fullerton, went with Lloyd into the Poás Volcano to find out more about the microbes there.

“Since joining Karen’s lab, I have been on four field expeditions where I quickly learned how critical clear communication and teamwork are for successful field science,” Fullerton says. “It has given me valuable experience that I will put to work once I graduate from UT.”

Lloyd’s passion for learning and exploring may have other important implications for our planet.

“Knowing about how carbon is distributed and how living things use it is crucial for understanding not only life cycles but also our environment,” Lloyd told Tennessee Today in 2018. “Since climate change is linked to carbon emissions, understanding how these microorganisms interact with carbon could help scientists produce mitigation strategies.”

Her discoveries might even provide a better understanding of how life formed on Earth and what life might look like on other planets.

But for now, Lloyd feels like she is barely scratching the surface of what is possible.

“We’re modern-day explorers. There’s so much that we don’t know. We have so much work left to do.”

Team members take samples and photos of a crater lake in the Poás Volcano.

UT 225th anniversaryThis story is part of the University of Tennessee’s 225th anniversary celebration. Volunteers light the way for others across Tennessee and throughout the world.

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Photos by Donato Giovannelli

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