Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A drop of ocean water tells a story

20.12.2002


Scientists are still learning what’s in a drop of ocean water, according to this week’s Nature Magazine. And the answers have implications for the whole planet, says co-author Craig Carlson, an oceanographer at the University of California, Santa Barbara. Carlson is an assistant professor in the Department of Ecology, Evolution and Marine Biology.



About ten thousand bacterioplankton of the type SAR 11 are found in every drop of seawater. And yet, as explained in the article, which gives the first accurate quantitative assessment of SAR 11, scientists are only beginning to understand what these organisms do.

The article is the result of a collaborative effort between Craig Carlson, and his lab, and Stephen Giovannoni of Oregon State University (OSU) and his lab, including first author Robert Morris. They are attempting to better understand the role of microbes in natural systems. The work was conducted under the Oceanic Microbial Observatory project, a joint effort between UCSB, OSU and the Bermuda Biological Station for Research that was initiated in 1999 by the National Science Foundation.


"Microbes like bacterioplankton are important biogeochemical agents," explained Carlson. "Over geologic time, they have played an important role in altering the chemical nature of the earths’s environment, allowing for the evolution of plants and animals. Without them, we would have no oxygen to breathe, organic matter would not be degraded, and the cycling of life’s essential nutrients would cease."

In a world that appears to be dominated by large organisms (i.e.things we can see), some might ask why we care about microbes –– don’t they just make us sick? The fact is that only a small percentage of microbes are pathogenic; most are beneficial to life on earth, according to Carlson. The living biomass and processes that drive the earth’s biosphere are really in the hands of the microbes.

For decades marine scientists have been able to enumerate bacterioplankton and scientists have known that they are important to the cycling of nutrients in the ocean. They have also known that there are many types (species, strains) of bacterioplankton in the oceans. But, until recently, the ability to distinguish one species from another in a quantitative manner was very limited. As a result, most oceanographers treat the bacterioplankton as a ’black box.’ "However, we know that all bacterial species do not function the same way, so the ’black box’ approach grossly oversimplifies microbial contributions," said Carlson. "One of the objectives of this study was to ’open up’ the ’black box’ and assess quantitatively how a specific group of bacterioplankton, called SAR 11, contribute to the total bacterial pool in the open ocean."

SAR 11, were first identified in the early 1990s by Steve Giovannoni from samples collected in the Sargasso Sea. They were identified qualitatively via gene cloning as a major group of uncultured bacterioplankton. Until now scientists haven’t had good quantitative information about how this specific group of bacteria contributed to the total oceanic bacterial pool. The use of molecular techniques in combination with microscopy now allows for the identification of certain bacteria types. The scientists found that the bacterioplankton SAR 11 comprises as much as 50 percent of the total surface microbial community (from zero to 140 meters below the surface) and 25 percent of the rest of the water column down to the bottom of the sea.

They were able to do this using a technique called "FISH," short for fluorescence in situ hybridization. The SAR 11 FISH probes, developed in Giovannoni’s lab, are short DNA sequences that have a fluorescent tag on them. Water drops containing one hundred thousand to millions of many different types of bacteria are concentrated onto a filter. Under special laboratory conditions the fluorescent DNA probe sticks to the targeted SAR 11 bacterial sequence and lights up like a Christmas tree bulb when exposed to a certain wavelength of light, and thus the SAR 11 can be counted.

Carlson said that "FISH" probe allows scientists to gain qualitative and quantitative information from a mixed bag of bacteria. "We can tell who they are and how many there are," said Carlson. "By sheer numbers, SAR 11 is important," said Carlson. "They are one of the most successful groups of bacteria in the ocean. The next step is to learn what they do. Identification is a first big step that allows us to assess their particular role in nature."


###
Craig Carlson can be reached at (805) 893-2541 or carlson@lifesci.ucsb.edu

Gail Gallessich | EurekAlert!
Further information:
http://www.ucsb.edu/

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

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

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>