Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nutrient supply after algal bloom determines the succession of the bacterial population

04.05.2012
To most people, algal blooms are an annoyance, which interferes with their summer days by the sea. In the coastal zone of temperate regions a spring algal bloom is not a sign of excessive nutrient input, but most of all a consequence of the more intense solar irradiation in spring.
Hence, spring algal blooms in these waters are a natural phenomenon. When algal blooms end the algae die and their remnants constitute an important nutrient supply for the whole ecosystem. This process is essential e.g. for the offshore abundance of fish.

But what exactly happens if an algal bloom ends? Hanno Teeling and Bernhard Fuchs and their colleagues from the Max Planck Institute in Bremen provide a surprising and very detailed answer, along with their coauthors from the Alfred Wegener Institute for Marine and Polar Research and the University of Greifswald.
They examined an algal bloom in the North Sea and were able to identify the role that the microorganisms play in the degradation of algal remnants and to gain insight into the degradation processes. And they discovered that some of these processes proceed differently than hitherto assumed. Their results were just published in the journal Science.

For their analyses the scientists filtrated several hundreds of liters of seawater on a regular basis for almost a year off the station ”Kabeltonne”, a long-term station of the Biologische Anstalt Helgoland that is part of the Alfred Wegener Institute. Hanno Teeling from the Max Planck Institute says: “Pelagic microorganisms, the so called bacterioplankton, are critical for the breakdown of the dead algal biomass. Especially the dynamic succession in the bacterioplankton caught our attention. Specialized bacterial populations accompany different phases of the algal bloom”. Processes within the bacterial population control the degradation of the algae, as the scientists could show.

His colleague Bernhard Fuchs who has been investigating the diversity and bacterioplankton composition for many years at the Max Planck Institute, adds: “For the first time we performed a high resolution analysis of the microbial community at genus level. We could not only identify the bacterial groups but also their functional tools, the enzymes, that are involved in the breakdown of the algal bloom”.

The scientists used a novel combination of techniques for their analyses. They determined the identity of the microorganisms by CARD-FISH, an in situ technology that can be applied directly to environmental samples. Additionally, they probed the bacterial population during and after the algal bloom by short sequences of a phylogenetic marker gene (16S rRNA pyrotag analyses). “By using a combination of metagenome and metaproteome analyses we succeeded to detect the active key enzymes in complex environmental samples. This allows us to infer the role of the respective bacterial groups from their metabolic function”, explains Thomas Schweder from the University of Greifswald. “This was only possibly by the computer-controlled integration of all data. For that task we used bioinformatics ”, as Frank Oliver Glöckner from the Max Planck Institute states. In the early phase of the algal bloom the scientists encountered a variety of enzymes for the degradation of complex algal carbohydrates such as laminarin. At a later stage transport proteins for peptides, short protein units, and transporters for the growth limiting nutrient phosphate and simple sugar components dominated the enzymatic cocktail. Noteworthy was the high portion of certain transport proteins, the TonB-dependent transporters that can transport larger molecules directly into the interior of the cells.
This discovery may disprove the conventional acceptance that long-chained molecules need to be broken up into smaller components before the cell can take them up. The TonB-transporter may enable the Flavobacteria, one of the dominating bacterial groups, to couple the assimilation and degradation and thus to gain a competitive advance towards other bacterial groups. At the end of the bloom the bacteria increasingly produced sulfatases that cleave sulfate esters from algae carbohydrates hard to decompose and thus allow the complete degradation of these substances. Hence, the scientists discovered a bacterial population in the algae bloom that did not only differ in its composition but also in its function from the bacterial community found in crystal clear, remote open waters.

The results of the study may help the scientists to resolve the so-called plankton paradox: How can so many plankton species coexist in a seemingly homogeneous habitat without competing for nutrients in a way that eliminates certain species? Rudolf Amann, Director of the Max Planck Institute explains: ”The secret at the level of the microorganisms is the heterogeneity of the microniches that the different groups inhabit. Thus, the specialized populations complement each other in the degradation of the organic matter.”

For further information please contact

Dr. Hanno Teeling hteeling@mpi-bremen.de
Dr. Bernhard Fuchs bfuchs@mpi-bremen.de
Prof. Dr. Rudolf Amann ramann@mpi-bremen.de

Or the public relation office
Rita Dunker rdunker@mpi-bremen.de
Manfred Schlösser mschloes@mpi-bremen.de

Original article

Substrate-controlled succession of marine bacterioplankton populations induced by a phytoplankton blom, 2012. H. Teeling, B. M. Fuchs, D. Becher, C. Klockow, A. Gardebrecht, C. M. Bennke, M. Kassabgy, S. Huang, A. J. Mann, J. Waldmann, M. Weber, A. Klindworth, A. Otto, J. Lange, J. Bernhardt, C. Reinsch, M. Hecker, J. Peplies, F. D. Bockelmann, U. Callies, G. Gerdts, A. Wichels, K. H. Wiltshire, F. O. Glöckner, T. Schweder, and R. Amann.
Science 4 May 2012: Vol. 336 no. 6081 pp. 608-611 DOI: 10.1126/science.1218344
Involved institutions

Max Planck Institute for Marine Microbiology, Bremen

Institute of Marine Biotechnology e.V., Greifswald

Jacobs University Bremen, Bremen

Alfred Wegener Institute for Polar and Marine Research, Biologische Anstalt
Helgoland, Helgoland
Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald

Pharmaceutical Biotechnology, Ernst-Moritz-Arndt University, Greifswald

DECODON GmbH, Greifswald
Ribocon GmbH, 28359 Bremen

Helmholtz-Zentrum Geesthacht, Center for Materials and Coastal Research, Geesthacht

Dr. Manfred Schloesser | Max-Planck-Institut
Further information:
http://www.mpi-bremen.de

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>