Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research spotlights a previously unknown microbial 'drama' playing in the Southern Ocean

31.07.2015

Discovery highlights both competition and cooperation between algae and bacteria for iron and vitamins that may have consequences for life in a warming ocean

A team of marine researchers funded by the National Science Foundation (NSF) has discovered a three-way conflict raging at the microscopic level in the frigid waters off Antarctica over natural resources such as vitamins and iron.


Electron micrograph of an Antarctic sea ice diatom, Amphiprora, with attached bacterial cells, illustrating the association between diatoms and bacteria in the Southern Ocean ecosystem

Credit: Greg Wanger

The competition has important implications for understanding the fundamental workings of globally significant food webs of the Southern Ocean, home to such iconic Antarctic creatures as penguins, seals, and orcas.

At the base of that food web are phytoplankton, single-celled organisms that survive by turning sunlight into food sources such as sugars and carbohydrates. Oceanographers have long recognized that iron fertilization in the Southern Ocean will drive phytoplankton blooms.

According to Andrew Allen, the senior author on the paper, the new research indicates that particular groups of bacteria, perhaps specifically cultivated by phytoplankton, are also important for regulating the magnitude of phytoplankton blooms. The bacteria also help sustain the phytoplankton by supplying them with vitamin B12.

Allen is jointly affiliated with the Scripps Institution of Oceanography (SIO) at the University of California, San Diego, and the Maryland-based J. Craig Venter Institute (JCVI).

The new findings, which were supported in part by an award from the Division of Polar Programs in NSF's Geosciences Directorate as well as by the Gordon and Betty Moore Foundation, may also be key to understanding how the vastly productive polar ecosystem might respond to future change caused by warming of the oceans.

The research was published this week in the Proceedings of the National Academy of Sciences.

Phytoplankton and bacteria form the base of the marine food web. The Southern Ocean encircling Antarctica is home to massive phytoplankton populations, and scientists have long considered their growth to be controlled primarily by the availability of iron and light.

"Through a combination of field experiments and sequencing, we have obtained a new view of the microbial interactions underpinning a highly productive ecosystem," said Allen.

The new research also may cause biologists to examine long-standing assumptions about the ecological balance of microbial communities in the Southern Ocean.

"I think this study also illustrates the eye-opening sensitivity of marine phytoplankton and bacteria to very minor additions of scarce micro-nutrients over very short--hourly--time scales," said Erin Bertrand, a former JCVI and SIO researcher and Division of Polar Programs' post-doctoral fellow, who is now an assistant professor at Dalhousie University in Halifax, Nova Scotia.

Bertrand, the lead author of the study added that "this suggests that these marine ecosystems are naturally poised to respond swiftly to changes in availability of these nutrients. It's likely that these states of resource boom and bust are a common, perhaps critical, feature of this remote environment."

With this new understanding of the nature of the interactions between microorganisms in the polar ocean and the careful balance of competitive and cooperative behaviors that exist in this key ecosystem, Allen noted, researchers can work towards predicting how these relationships might change in the future.

The team's findings are based on research supported by the U.S. Antarctic Program in and around McMurdo Station, the largest year-round research station in Antarctica. NSF manages the U.S. Antarctic Program.

Flying aboard helicopters based at McMurdo, the research team ventured out to the edge of the sea ice in McMurdo sound, where they carefully collected water samples from the sunlit surface and returned them to the Albert P. Science and Engineering Center at McMurdo, in order to perform experiments.

The researchers learned that although the water appeared teeming with a particular type of phytoplankton, called diatoms, the diatoms were malnourished.

Unlike most regions of the global ocean which do not contain sufficient nitrogen or phosphorous for sustained phytoplankton growth, diatoms in the remote waters of McMurdo Sound were starving from lack of iron and deficiency of vitamin B12.

"Just like humans, phytoplankton require vitamins, including vitamin B12, to survive," said Bertrand.

She added, "We've shown that the phytoplankton in McMurdo Sound acquire this precious resource from a very specific group of bacteria. Those bacteria, in turn, appear to depend directly on phytoplankton to supply them with food and energy."

Results of the study, however, suggest that here is where it gets messy.

A different group of bacteria, also relying on the phytoplankton for food and energy, appear to compete with the diatoms for the precious vitamin, and all three groups of microbes are competing for iron, which, due to the extreme remoteness of the Southern Ocean, is a scarce and consequently invaluable resource.

The result, the researchers said, is a new picture of a precariously balanced system, full of microbial drama over the competiton for survival.

The team further confirmed that a large portion of the B12 supply in the Southern Ocean appears to be produced by a particular group of bacteria belonging to the Oceanospirllaceae. This aspect of this study was facilitated by collaboration with researchers at the University of Rhode Island (URI) and the Marine Biological Laboratory in Woods Hole, Mass. which have been conducting studies on bacteria in and around the Amundsen Sea, another region of the Southern Ocean.

Media Contact

Peter West
pwest@nsf.gov
703-292-7530

 @NSF

http://www.nsf.gov 

Peter West | EurekAlert!

Further reports about: Antarctic Antarctica Ecosystem Ocean Polar bacteria blooms diatoms microbial phytoplankton blooms

More articles from Earth Sciences:

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

nachricht Modeling magma to find copper
13.01.2017 | Université de Genève

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>