Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microbe DNA helps scientists understand ocean

22.02.2006


Using DNA analysis, MIT researchers and colleagues have gained new insight into how marine microbes thrive and survive at different depths of the ocean.

"Microbes are the central processors of matter and energy in almost every ecosystem imaginable - especially so in the sea," said MIT Professor Ed DeLong, who led the work. Thousands of different types of microbes, the world’s smallest creatures, inhabit every cubic centimeter of seawater. They have huge effects on ocean chemistry and possibly even climate.

However, "their complex interactions are really tough to study in natural environments," DeLong said. "We took a shortcut to understanding their environmental activities by analyzing the DNA from whole communities of microbes."



In the Jan. 27 issue of Science, the researchers describe their analysis of DNA from microbe communities at seven different depths in the tropical Pacific Ocean, from the surface down to 4,000 meters (about 13,000 feet). One of the team’s overall goals was to determine how the microbes near the surface are different from those that live thousands of meters down.

The scientists collected water from the open ocean about 100 kilometers (60 miles) north of the island of Oahu. This spot, site of the Hawaii Ocean Time Series station, has been studied continuously for 18 years by one of the co-authors, David Karl of the University of Hawaii. It was chosen because it is far from any terrestrial influences, yet its chemistry and (nonmicrobial) biology are relatively well known.

Still, challenges remained. Because concentrations of microbes were so low in this "oceanic desert" area, the team had to spend five to six hours filtering up to 600 liters (160 gallons) of seawater for each sample to obtain enough microbial DNA for analysis.

What did the researchers find?

Not surprisingly, in samples from the sunlit waters within about 100 meters of the surface, they discovered many microbial DNA sequences that were associated with photosynthesis. This indicates that many microbes in these waters probably use sunlight as a source of energy.

Surface samples also contained microbial DNA associated with movement and propulsion. "This suggests that movement may be especially important for surface-water microbes, perhaps helping them follow chemical gradients or move from food particle to food particle," said DeLong, who has appointments in the Department of Civil and Environmental Engineering (CEE) and in the Biological Engineering Division.

In contrast, DNA from microbes in deeper waters suggests many may survive by attaching to and breaking down particles of organic material. Such particles continually sink down from the surface waters into the deep sea, providing food for many organisms in the form of "marine snow."

Perhaps the most surprising finding was the large amount of DNA that came from viruses, especially in near-surface waters. Since the researchers excluded free-living viruses from their initial sample, they believe that this viral DNA must have come from viruses that had infected living bacteria.

"We’re excited about these new views of microbes we and others are developing by analyzing microbial genomes recovered directly from the environment. The approach is really providing new insight into what makes microbes tick in the real world - how they affect each other and influence their surrounding environment," DeLong said.

DeLong’s colleagues from MIT are Penny Chisholm, the Lee and Geraldine Martin Professor of Environmental Studies in CEE and the Department of Biology; CEE postdoctoral associates Tracy Mincer, Steven Hallam (now at the University of British Columbia), Matthew Sullivan and Niels-Ulrik Frigaard (now at the University of Copenhagen); Virginia Rich, a graduate student in the MIT-Woods Hole Oceanographic Institution Joint Program; and CEE research scientist Asuncion Martinez.

Additional authors of the Science paper are from the Monterey Bay Aquarium Research Institute, the University of Hawaii and San Diego State University.

This work was funded by the Gordon and Betty Moore Foundation, the National Science Foundation, and the U.S. Department of Energy Microbial Genomics Program.

Elizabeth A. Thomson | MIT News Office
Further information:
http://www.mit.edu

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>