Diving deep into the world of microbes

by Erik Olsen  |  March 16, 2018

It’s the little things that count. Just ask Anna-Louise Reysenbach. Dr. Reysenbach is the Chief scientist of the Brothers volcano expedition, and her specialty is microbes, particularly the infinitesimally small creatures that occupy some of the most punishing environments on earth.

Called thermophiles (lovers of heat) these organisms constitute thousands of species, and more are being discovered all the time. Many thermophiles are Archaea, a group of organisms that only in the 1970s came to be recognized as its own entire domain of life. (The two other domains are Eukarya—multicellular organisms from plants to animals to fungus, and Bacteria). In fact, Archaea are thought to be among the earliest organisms to have ever existed.

Thermophiles can be found in geothermal hot places around the planet, like the hot springs in Yellowstone National Park as well as around deep sea hydrothermal vents. Which is one reason why we are here at Brothers volcano, part of one of the earth’s most geothermically active regions.

Over the course of the expedition, we will be collecting large quantities of microbes from around the vents; we’ll study them under the microscope and we’ll even sequence their DNA. There’s an excellent chance that we will even discover species entirely new to science.

“We really know very little about the microbial world, and deep sea vents and volcanoes are one of the last frontiers where we can study them and even discover new branches of life,” says Reysenbach.

Which is why Dr. Reysenbach is co-leading the expedition here at Brothers. There is simply so much new knowledge to gain, some of which can result in direct benefit to humans. For example, Taq polymerase is an enzyme that was discovered in a thermophile from a hot spring in Yellowstone National Park. The enzyme has revolutionized the biosciences because it enables us to generate multiple copies of a single gene, creating huge advances in molecular biology and biotechnology.

“It’s a multibillion dollar enzyme,” says Reysenbach.

Last night was the first big dive for Reysenbach’s group of young microbe specialists, Team Microbe. For several hours, deep into the night, Jason prowled the Northwest caldera of the Brothers volcano, looking for the hot vents where microbes thrive. Finding them is not particularly difficult, but Reysenbach says it helps to think like a microbe, and to harbor a deep appreciation for them.

“When I get down to the bottom of the ocean, I’m always in awe of all the microbial biomass. All this slime and color covering the rocks,” she says.

Sure enough, during the dive we found several smoking chimneys slathered in slime, and using Jason’s mechanical arm, a pilot reached out and plucked a few sections right off the volcano, placing them in closed containers we call “chamber pots”. The pots came to the surface, and Team Microbe immediately sampled the microbial material off the rocks, placing them in test tubes to keep them free of oxygen.

“What we’re interested in doing is figuring out what organisms are on those chimneys and what are they doing?” she says.

The team is now extracting DNA from the microbes we collected to obtain the genetic information that tells us what they are.  “DNA is the fingerprint of life.  From that DNA, we can actually reconstruct the entire genomes of all the organisms associated with these rocks.”

That’s the “who are they part” of the equation.

To figure out the “what they are doing” part, the team will grow them in the lab and then figure out what kind of energy they need, and how they use carbon to live. Reysenbach says that there are bound to be discoveries ahead:

“The exciting thing about being a microbial ecologist is you realize that there is so much still to be discovered on this planet. There is much more diversity out there than we ever, ever, ever ever imagined.”