Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Barren' seafloor teeming with microbial life

30.05.2008
Life at rock bottom great for bacteria

Once considered a barren plain with the odd hydrothermal vent, the seafloor appears to be teeming with microbial life, according to a paper being published May 29 in Nature.

“A 60,000 kilometer seam of basalt is exposed along the mid-ocean ridge spreading system, representing potentially the largest surface area for microbes to colonize on Earth,” said USC geomicrobiologist Katrina Edwards, the study’s corresponding author.

While seafloor microbes have been detected before, this is the first time they have been quantified. Using genetic analysis, Edwards and colleagues found thousands of times more bacteria on the seafloor than in the water above.

... more about:
»Edwards »USC »diversity »geobiology »microbes »microbial

Surprised by the abundance, the scientists tested another Pacific site and arrived at consistent results. This makes it likely that rich microbial life extends across the ocean floor, Edwards said.

The scientists also found higher microbial diversity on the rocks compared with other vibrant systems, such as those found at hydrothermal vents.

Even compared with the microbial diversity of farm soil—viewed by many as the richest—diversity on the basalt is statistically equivalent.

“These scientists used modern molecular methods to quantify the diversity of microbes in remote deep-sea environments,” said David L. Garrison, director of the National Science Foundation’s biological oceanography program.

“As a result, we now know that there are many more such microbes than anyone had guessed,” he added.

These findings raise the question of where these bacteria find their energy.

“We scratched our heads about what was supporting this high level of growth when the organic carbon content is pretty darn low,” Edwards recalled.

With evidence that the oceanic crust supports more bacteria compared with overlying water, the scientists hypothesized that reactions with the rocks themselves might offer fuel for life.

Back in the lab, they calculated how much biomass could theoretically be supported by chemical reactions with the basalt. They then compared this figure to the actual biomass measured. “It was completely consistent,” Edwards said.

This lends support to the idea that bacteria survive on energy from the crust, a process that could affect our knowledge about the deep-sea carbon cycle and even evolution.

For example, many scientists believe that shallow water, not deep water, cradled the planet’s first life. They reason that the dark carbon-poor depths appear to offer little energy, and rich environments like hydrothermal vents are relatively sparse.

But the newfound abundance of seafloor microbes makes it theoretically possible that early life thrived—and maybe even began—on the seafloor.

“Some might even favor the deep ocean for the emergence of life since it was a bastion of stability compared with the surface, which was constantly being blasted by comets and other objects,” Edwards suggested.

Still, current knowledge of the deep biosphere can fit on the head of a pin, Edwards said. Most seafloor bacteria uncovered in this study show little relation to those cultivated in labs, which makes experimentation difficult.

Rather than bringing bacteria to the lab, however, Edwards plans to bring the lab to bacteria—with a microbial observatory 15,000 feet below sea level.

Thanks to a $3.9-million grant awarded in March by the Gordon and Betty Moore Foundation, Edwards and over 30 colleagues will continue studying seafloor bacteria, but will also study their subseafloor cousins that cycle through the porous rock.

The first expedition of its kind, the drilling operation will penetrate 100 meters of sediments and 500 meters of bedrock.

Besides experiments aimed at learning how precisely these bacteria alter rock, the scientists will measure the diversity, abundance and relatedness of microbes at different depths.

This will shed light on whether the bacteria evolved from ancestors that floated down from above or from some as yet unknown source deep in the crust.

The Nature study provides a crucial base of comparison between the seafloor and subseafloor microbes, both completely unknown until just recently.

The decade-long undertaking will further bridge the earth and life sciences, a key goal in the emerging field of geobiology, described by Edwards as the co-evolution of Earth and life.

The deep biosphere is uniquely suited for a geobiological approach, Edwards said, since a proper understanding requires genomics, analysis of microbe-rock chemical interactions and a timescale in the millions of years.

Edwards joined USC two years ago as part of its cluster hire of scientists with multidisciplinary interests related to geobiology. With its concentration of faculty in the field, Southern California and USC in particular are regarded as hubs for the geobiology research community.

USC recently hosted the 5th Annual Geobiology Symposium, co-organized by USC post-doctoral student Beth Orcutt, the second author of the Nature paper.

In addition, the USC Wrigley Institute for Environmental Studies runs a summer geobiology course on Catalina Island that brings together top students and faculty.

Edwards believes that most people just don’t realize how much life thrives in the watery depths.

“If we can really nail down what’s going on, then there are significant implications,” she said. “It is my hope that people turn their heads and notice that there’s life down there.”

Terah DeJong | EurekAlert!
Further information:
http://www.usc.edu

Further reports about: Edwards USC diversity geobiology microbes microbial

More articles from Life Sciences:

nachricht Flavins keep a handy helper in their pocket
25.04.2018 | University of Freiburg

nachricht Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Getting electrons to move in a semiconductor

25.04.2018 | Physics and Astronomy

Reconstructing what makes us tick

25.04.2018 | Physics and Astronomy

Cheap 3-D printer can produce self-folding materials

25.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>