Montana State scientist wins grant to study how deep-sea microbes break down carbon
BOZEMAN – A Montana State University biochemist whose microbial research frequently takes him to hot springs in Yellowstone National Park will travel to the ocean floor this fall to collect microorganisms that live in the deep sea.
Roland Hatzenpichler and his colleagues will board a submersible in November that will take them down 6,500 feet to the bottom of Guaymas Basin in the Gulf of California to extract core samples of the hydrothermally active microbe-rich sediments found there. The scientists plan to use newly developed technology to research the samples to gain a better understanding of what microbes live in the sediments and what role they play in breaking down and converting carbon.
"One teaspoon of deep-sea mud harbors more species of microorganisms than there are species of mammals on our entire planet," said Hatzenpichler, assistant professor in the Department of Chemistry and Biochemistry in MSU's College of Letters and Science. "Those microorganisms help break down dead biomass – from fish to algae – that fall to the ocean floor or, in the case of natural oil or hydrocarbon gases, seep up from below-ground reservoirs."
Hatzenpichler said that the biomass that collects on the ocean floor adds about an inch to the basin's sediment layer every 25 years, a growth rate that is higher than in most other places in the world. Additionally, the temperatures of the basin's sediment often reach or exceed 212 degrees Fahrenheit, the boiling point of water at sea level. The combination of these two factors makes the area a hotbed of microbial activity.
What scientists don't really know, he said, is what happens to all the energy and "yummy carbon available to that ecosystem," and what role different microorganisms play in breaking down these complex carbon molecules, because it's nearly impossible to re-create the natural ecosystem in a laboratory setting.
He explained that in the sunlit surface waters, phytoplankton, like trees, remove carbon dioxide from the atmosphere. But, after they die, the phytoplankton sink to the bottom of the ocean and the previously fixed carbon then becomes available to the sediment-dwelling microbes.
"We can measure how much phytoplankton and other lifeforms die and drop to the bottom and we can measure how much gas is bubbling up from the bottom, but we have no idea what is happening in between," Hatzenpichler said. "We need to have an understanding of how microbes break down and convert these complex carbon compounds."
Along with Brett Baker of the University of Texas at Austin and Andreas Teske of the University of North Carolina Chapel Hill, Hatzenpichler will use a $1 million grant from the National Science Foundation to use recently developed techniques to learn more about the broad range of microorganisms found in the basin — many of which have never been experimentally analyzed in any ecosystem — and what functions they perform when breaking down organic carbon.
The goal of the project, Hatzenpichler said, is to provide a benchmark study for the developing field of deep-sea sediment microbiology and lay the foundation for future physiological studies in environmental microbiology.
"What's new about our research is we will go beyond DNA sequencing on the microorganisms to learn what genes are present in the genomes and what these genes could be doing," said Hatzenpichler who is leading the project. "Based on biochemistry research of the past 50 years, we can come up with an idea of the physiology of the organism – its carbon source, its energy source, its nitrogen source, how it might interact with its environment and other organisms."
However, he said, DNA sequencing can only tell part of the story.
"We also need to know what the environmental conditions are in order to understand if the microorganisms are doing what we actually think they could be doing," Hatzenpichler said. "They could be doing one thing at one time and the environmental conditions change and then they start doing something completely different."
Teske, a geochemist, will lead the sample collection and characterize what organisms, chemicals, carbon sources and energy sources are present at the collection site, as well as characterize ecosystem conditions such as water temperature and oxygen levels, Hatzenpichler said. Baker, whose expertise is metagenomics, will lead the DNA sequencing and genome analyses efforts to find out which microbes are present and what functions they might be capable of performing.
Hatzenpichler said his role is to follow up with experiments in the lab and on the research cruise to determine whether the processes Baker predicted from the organisms' genomes are actually occurring.
The research is important, he said, because oceans cover more than 70 percent of the planet and the deep sea is the largest unexplored area on Earth.
"We're talking about very large amounts of material that is being degraded in oceans every day and we have no idea how this is being performed," Hatzenpichler said. "So, on a very fundamental level, we need to understand how the atmosphere, the deep sea and the water column are connected through biogeochemical cycling of elements."
Additionally, understanding how the microorganisms break down the naturally occurring gases, natural oil and dead biomass in the deep sea could potentially lead to exploiting those enzymes to clean up oil spills or other contaminants that are hard to break down, he said.
Mary Cloninger, head of MSU's Department of Chemistry and Biochemistry, said this project demonstrates Hatzenpichler's broad range of expertise in his field and the importance of MSU research close to home and beyond.
"Dr. Hatzenpichler's research program perfectly highlights the fact that research at MSU is important locally to help us understand microorganisms in Yellowstone National Park, while also contributing to important studies in faraway areas such as the Gulf of California," Cloninger said. "This new project also highlights Dr. Hatzenpichler's creative and broad-scope approach to better understanding the organisms that influence our environment. I'm looking forward to the results that Dr. Hatzenpichler and his colleagues will discover in this project."
In 2017, Hatzenpichler was named a NASA Early Career Fellow for his research on multicellular bacteria. In addition to the Department of Chemistry and Biochemistry he is affiliated with MSU's Center for Biofilm Engineering and the Thermal Biology Institute. Research in his lab is supported by the National Science Foundation, NASA and the Gordon and Betty Moore Foundation's Marine Microbiology Initiative. For more information about research in the Hatzenpichler lab, go to http://www.environmental-microbiology.com.