Beneath the ocean floor is a desolate place with no oxygen and sunlight. Yet microbes have thrived in this environment for millions of years.
This is an image of archaea.
Credit: Richard Kevorkian, University of Tennessee
Scientists have puzzled over how these microbes survive, but today there are more answers.
A study led by Karen Lloyd, a University of Tennessee, Knoxville, assistant professor of microbiology, reveals that these microscopic life-forms called archaea slowly eat tiny bits of protein. The study was released today in Nature.
The finding has implications for understanding the bare minimum conditions needed to support life.
"Subseafloor microbes are some of the most common organisms on earth," said Lloyd. "There are more of them than there are stars or sand grains. If you go to a mud flat and stick your toes into the squishy mud, you're touching these archaea. Even though they've literally been right under our noses for all of human history, we've never known what they're doing down there."
Archaea are one of three life forms on earth, including bacteria and eukarya cells.
Scientists are interested in archaea's extreme way of life because it provides clues about the absolute minimum conditions required to sustain life as well as the global carbon cycle.
"Scientists had previously thought that proteins were only broken down in the sea by bacteria," said Lloyd. "But archaea have now turned out to be important new key organisms in protein degradation in the seabed."
Proteins make up a large part of the organic matter in the seabed, the world's largest deposit of organic carbon.
To reveal the cells' identities and way of life, Lloyd and her colleagues collected ocean mud containing the archaea cells from Aarhus Bay, Denmark. Then they pulled out four individual cells and sequenced their genomic DNA to discover the presence of the extracellular protein-degrading enzymes predicted in those genomes.
"We were able to go back to the mud and directly measure the activity of these predicted enzymes," said Andrew Steen, another UT researcher and coauthor of the study. "I was shocked at how high the activities were."
This novel method opens the door for new studies by microbiologists. Scientists have been unable to grow archaea in the laboratory, limiting their studies to less than one percent of microorganisms. This new method allows scientists to study microorganisms directly from nature, opening up the remaining 99 percent to research.
Lloyd collaborated with other researchers from UT, as well as, Aarhus University in Denmark, Bigelow Laboratory for Ocean Sciences in Maine, Ribocon GmbH in Germany, and the Max Planck Institute for Marine Biology in Germany.
Whitney Heins | EurekAlert!
Two decades of training students and experts in tracking infectious disease
27.11.2015 | Hochschule für Angewandte Wissenschaften Hamburg
Increased carbon dioxide enhances plankton growth, opposite of what was expected
27.11.2015 | Bigelow Laboratory for Ocean Sciences
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...
25.11.2015 | Event News
17.11.2015 | Event News
21.10.2015 | Event News
27.11.2015 | Press release
27.11.2015 | Life Sciences
27.11.2015 | Materials Sciences