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!
Learning from Nature: Genomic database standard alleviates search for novel antibiotics
02.09.2015 | Max-Planck-Institut für marine Mikrobiologie
Orang-utan females prefer cheek-padded males
02.09.2015 | Max Planck Institute for Evolutionary Anthropology, Leipzig
China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed.
China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from...
The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.
Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient...
Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.
"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...
A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...
A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...
20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
02.09.2015 | Physics and Astronomy
02.09.2015 | Life Sciences
02.09.2015 | Awards Funding