Nav: Home

Microorganisms in the subsurface seabed on evolutionary standby

March 20, 2017

Researchers at the Center for Geomicrobiology at Aarhus University, Denmark, have sequenced the genomes of several microorganisms inhabiting the subsurface seabed in Aarhus Bay. The results reveal the extreme evolutionary regime controlling microbial life in the deep biosphere.

A life in slow motion

Microbial evolution is arrested in the subsurface seabed as cells are buried in under a continuously growing layer of deposited mud and their genetic material therefore remains unchanged during the millennia.

"This means that these buried microorganisms presumably have a very low adaptability, unlike the microbial life that otherwise surrounds us in our environment" says Kasper U. Kjeldsen, associate professor at the Center for Geomicrobiology, who participated in the research project.

Through genetic mutations microorganisms normally have the ability to develop new properties over a short time scale, thereby quickly adapting in response to their environment. But the researchers have shown that microbes grow in slow motion in the deep seabed with generation times of up to 100 years. Mutations therefore appear and spread very slowly in the subsurface populations. For comparison, intestinal bacteria typically have generation times of 20 minutes.

The microorganisms in the deep seabed live in an environment, which is extremely poor in food. Put simply, they chew on a lunch box, which has fed their ancestors for thousands of years, and the availability of energy is therefore minimal.

Buried alive

The microbial species we find in the deep seabed, are the same as those who lived at the seafloor for thousands of years ago. Unlike the majority of the members of surface community, these microorganisms survive burial deeper and deeper in to the subsurface.

It remains a mystery why these microorganisms have an inherent ability to grow under the extreme conditions that occur in the deep seabed.

The researchers hope that the new findings could ultimately help us to understand and reconstruct past environmental and climatic conditions based on analysis of the microbial species composition in deep marine sediment cores.

The discovery, which has changed our understanding of microbial life in the soil deep biosphere, was recentlt published in the highly acclaimed international journal Proceedings of the National Academy of Sciences of the United States America (PNAS).
-end-
CONTACT

Associate Professor Kasper U. Kjeldsen
Email: kasperuk@bios.au.dk
www: http://pure.au.dk/portal/en/
Phone: +45 8715 6506

Professor Andreas Schramm
Email: andreas.schramm@bios.au.dk
www: http://pure.au.dk/portal/en/
Phone: +45 8715 6541

Center for Geomicrobiology and Section for Microbiology, Department of Bioscience, Aarhus University.

Aarhus University

Related Microorganisms Articles:

Soil scientist researches nature versus nurture in microorganisms
Ember Morrissey, assistant professor of environmental microbiology at West Virginia University, uncovered that nature significantly affects how the tiny organisms under our feet respond to their current surroundings.
Microorganisms reduce methane release from the ocean
Bacteria in the Pacific Ocean remove large amounts of the greenhouse gas methane.
Microorganisms build the best fuel efficient hydrogen cells
With billions of years of practice, nature has created the most energy efficient machines.
How microorganisms protect themselves against free radicals
There are numerous different scenarios in which microorganisms are exposed to highly reactive molecules known as free radicals.
Scientists' warning to humanity: Microbiology and climate change
When it comes to climate change, ignoring the role of microorganisms could have dire consequences, according to a new statement issued by an international team of microbiologists.
Climate change could affect symbiotic relationships between microorganisms and trees
An international research consortium mapped the global distribution of tree-root symbioses with fungi and bacteria that are vital to forest ecosystems.
Microorganisms on microplastics
A recent study shows that that the potentially toxin-producing plankton species Pfiesteria piscicida prefers to colonize plastic particles, where they are found in 50 times higher densities than in the surrounding water of the Baltic Sea and densities about two to three times higher than on comparable wood particles floating in the water.
Harnessing microorganisms for smart microsystems
A research team at the Department of Mechanical Engineering at Toyohashi University of Technology has developed a method to construct a biohybrid system that incorporates Vorticella microorganisms.
Microorganisms are the main emitters of carbon in Amazonian waters
A study performed with microorganisms inhabiting floodplains, which comprises 20 percent of the whole Amazon, showed that the microbial food chain produces 10 times more CO2 than the classical food chain, mostly by decomposing organic matter.
Plant seed research provides basis for sustainable alternatives to chemical fertilizers
Scientists assessed the seed microbiomes of two successive plant generations for the first time and discovered that seeds are an important vector for transmission of beneficial endophytes across generations.
More Microorganisms News and Microorganisms 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

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.