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 A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>