Nav: Home

Study shows unusual microbes hold clues to early life

February 07, 2019

A new study has revealed how a group of deep-sea microbes provides clues to the evolution of life on Earth, according to a recent paper in The ISME Journal. Researchers used cutting-edge molecular methods to study these microbes, which thrive in the hot, oxygen-free fluids that flow through Earth's crust.

Called Hydrothermarchaeota, this group of microbes lives in such an extreme environment that they have never been cultivated in a laboratory for study. A research team from Bigelow Laboratory for Ocean Sciences, the University of Hawai'i at Manoa, and the Department of Energy Joint Genome Institute bypassed the problem of cultivation with genetic sequencing methods called genomics, a suite of novel techniques used to sequence large groups of genetic information. They found that Hydrothermarchaeota may obtain energy by processing carbon monoxide and sulfate, which is an overlooked metabolic strategy. The microbes use energy from this process to grow as a form of chemosynthesis.

"The majority of life on Earth is microbial, and most microbes have never been cultivated," said Beth Orcutt, a senior research scientist at Bigelow Laboratory and one of the study's senior authors. "These findings emphasize why single cell genomics are such important tools for discovering how a huge proportion of life functions."

Analyzing Hydrothermarchaeota genomes revealed that these microbes belong to the group of single-celled life known as archaea and evolved early in the history of life on Earth - as did their unusual metabolic processes. These observations suggest that the subsurface ocean crust is an important habitat for understanding how life evolved on Earth, and potentially other planets.

The researchers also found genetic evidence that Hydrothermarchaeota have the ability to move on their own. Motility offers a valuable survival strategy for the extreme environment they call home, which has a limited supply of nutrients essential to life.

"Studying these unique microbes can give us insights into both the history of Earth and the potential strategies of life on other planets," said Stephanie Carr, first author on the paper and a former postdoctoral researcher with Orcutt who is now an assistant professor at Hartwick College. "Their survival strategies make them incredibly versatile, and they play an important, overlooked role in the subsurface environments where they live."

In 2011, Orcutt and other project scientists sailed to the flank of the Juan de Fuca Ridge, a mid-ocean ridge off the coast of Washington where two ocean plates are separating and generating new oceanic crust. They used Woods Hole Oceanographic Institution's deep-diving robot Jason to travel 2.6 km to the seafloor and collect samples of the fluid that flows through the deep crust.

These crustal fluids contained microbes that had never before been studied. Working in partnership with the Department of Energy Joint Genome Institute, the researchers sorted and analyzed the microbes in the Single Cell Genomics Center at Bigelow Laboratory. This cutting-edge research facility is directed by Ramunas Stepanauskas, a senior research scientist and study author. The project team also analyzed the microbes using metagenomics, a technique that extracts genomic information directly from environmental samples. These analyses yielded insights into the genetic blueprints of Hydrothermarchaeota, their relationship to other archaea, and the strategies they have evolved to survive in the subseafloor.

The researchers will build upon this discovery when they return to the Juan de Fuca Ridge in May 2019 to continue investigating the extreme microbes thriving below the seafloor. Orcutt will lead a cruise using ROV Jason with this team of researchers to further explore the subseafloor environment, leveraging funding from the National Science Foundation and NASA.

"The microbes living 'buried alive' below the seafloor are really intriguing to us, since they can survive on low amounts of energy," Orcutt said. "We hope that our experiments on these weird microbes can show how they do this, so we can imagine how life might exist on other planets."
-end-
This work was supported by the National Science Foundation, the NASA Astrobiology Institute, the Department of Energy Joint Genome Institute, and the Center for Dark Energy Biosphere Investigations (C-DEBI).

Bigelow Laboratory for Ocean Sciences is an independent, nonprofit research institute on the coast of Maine. Its research ranges from the microscopic life at the bottom of marine food webs to large-scale ocean processes that affect the entire planet. Recognized as a leader in Maine's emerging innovation economy, the Laboratory's research, education, and technology transfer programs are contributing to significant economic growth. Learn more at bigelow.org, and join the conversation on Facebook, Instagram, and Twitter.

Bigelow Laboratory for Ocean Sciences

Related Microbes Articles:

Rye is healthy, thanks to an interplay of microbes
Eating rye comes with a variety of health benefits. A new study from the University of Eastern Finland now shows that both lactic acid bacteria and gut bacteria contribute to the health benefits of rye.
Gut microbes may affect the course of ALS
Researchers isolated a molecule that may be under-produced in the guts of patients.
Gut microbes associated with temperament traits in children
Scientists in the FinnBrain research project of the University of Turku discovered that the gut microbes of a 2.5-month-old infant are associated with the temperament traits manifested at six months of age.
Gut microbes eat our medication
Researchers have discovered one of the first concrete examples of how the microbiome can interfere with a drug's intended path through the body.
Microbes can grow on nitric oxide
Nitric oxide (NO) is a central molecule of the global nitrogen cycle.
More Microbes News and Microbes Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...