Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Life Underground: Microbes Active Far Beneath Seafloor

14.06.2013
Microbes are living more than 500 feet beneath the seafloor in 5 million-year-old sediment, according to new findings by researchers at the University of Delaware and Woods Hole Oceanographic Institution (WHOI).

Genetic material in mud from the bottom of the ocean — called the deep biosphere —revealed an ecosystem of active bacteria, fungi and other microscopic organisms at depths deeper than a skyscraper is high. The findings were published in Nature on June 12.

“This type of examination shows active cells,” said co-author Jennifer F. Biddle, assistant professor of marine biosciences in UD’s College of Earth, Ocean, and Environment. “We knew that all of these cells were buried, but we didn’t know if they were doing anything.”

In fact, the microbes are reproducing, digesting food and even moving around despite the extreme conditions found there: little to no oxygen, heavy pressure and minimal nutrient sources. The organisms could shed light on how carbon and other elements circulate in the environment, the scientists reported.

Extracting the data

The researchers analyzed messenger RNA (mRNA) in sediment from different depths collected off the coast of Peru in 2002 during Leg 201 of the Ocean Drilling Program. This first glimpse into the workings of the heretofore hidden ecosystem was made possible by the first successful extraction of total mRNA, or the “metatranscriptome,” from the deep biosphere.

Messenger RNA is highly sought-after by microbial ecologists because its presence indicates that the cells that made it are alive and because it carries the instructions for the proteins the cells are making. But because the metabolic rates in the deep biosphere are very low and mRNA is present in small amounts, extracting enough of it to analyze from deep sediments had been thought by many scientists to be impossible.

“It’s not easy,” said lead author William Orsi, a postdoctoral researcher advised by Biddle and WHOI’s Virginia Edgcomb. “There’s a certain amount of banging your head against the wall before it works.”

The genetic sequencing was performed at the Delaware Biotechnology Institute, generating more than a billion bases of information. UD’s Glenn Christman, who received a master’s degree in marine biosciences and works in Biddle’s lab as a bioinformatician, created new computer programs to help examine the immense amount of data.

Determining microbial activity

The team found evidence of cell division occurring in all three domains of life: bacteria; single-celled archaea, commonly found in oceans; and eukaryotes (organisms with nucleus-containing cells), specifically fungi.

Other researchers previously suggested that cells in the deep biosphere were buried many years ago and continued to survive by essentially repairing themselves. The new findings show, however, that these cells are able to divide and create new cells.

“It’s the first time it’s been seen,” Biddle said, adding that researchers do not know how long it takes for a cell to divide, but it could be on a geologic timescale of thousands of years.

Messenger RNAs coding for enzymes involved in sulfate reduction and nitrate reduction, processes cells use to generate energy-storing molecules, also were found.

“It’s been theorized that much of the energy that microbes get in this environment comes from sulfate reduction,” said Orsi. “Basically, instead of breathing with oxygen, they ‘breathe’ with sulfate.”

Until now, models of microbial activity in deep sediments have included sulfate reduction but have not included significant use of nitrate. The current research found comparable numbers of mRNAs involved in nitrate reduction and sulfate reduction, suggesting that both processes are important in the deep biosphere community.

The researchers also found evidence that cells in the deep biosphere are eating amino acids, which are a rich source of carbon and nitrogen and can only come from other living (or recently deceased) organisms.

They think those dead or dying cells are native to the deep biosphere rather than remnants that drifted down through the water because most of the dead material that reaches the seafloor from above is rapidly eaten. Deeper than a few centimeters down, most of the amino acids come from cells that lived and died there.

“By the time you get 100 meters down, the bacteria are eating the leftovers of the leftovers of the leftovers of the leftovers — and they are still yummy for bacteria,” Biddle said.

The study also showed that these deep biosphere microbes can move, which was previously in question. Genetic material indicated that some of the cells have flagella, or small tails that can propel them forward. Other cells produced mRNAs related to gliding and twitching. The ability to move was linked to how porous the sediment was.

“It’s reminiscent of that line from Jurassic Park, ‘Life finds a way,’” Biddle said. “If there’s space to move, they move.”

Broader implications

Finding life in the deep biosphere could refine understanding how carbon moves through the environment. Longtime global models show carbon sinking into ocean sediment, getting buried deeper and deeper and eventually getting released from within Earth’s crust through a volcano.

“But there’s something happening to it on the way down,” Biddle said. “Models suggest that activity in the subsurface is not that important, but we’d like to revisit that with this new information.”

Another reason could be to explore for new pharmaceutical ingredients. The researchers found antibiotic defense mechanisms showing in the RNA data, possibly representing a “seed bank” for medical advances in antibiotics, antifungals and immunosuppressants.

Now that a new approach to analyzing the mRNA has been developed, Biddle is interested in studying other sites beyond the Peru Margin, where the water depth is about 150 meters and there are high sedimentation rates. The activity and depth of the water above the seafloor may impact the microbial ecosystems that exist below.

“This is just this one site in one place, and there’s still the rest of the world to go explore,” Biddle said. “This kind of data is going to be possible to get from other areas, and this should hopefully be the groundwork for it.”

The research was funded by grants from the National Science Foundation and the Center for Dark Energy Biosphere Investigations.

Article by Teresa Messmore, with material from Woods Hole Oceanographic Institution

Andrea Boyle Tippett | Newswise
Further information:
http://www.udel.edu

More articles from Life Sciences:

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>