Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Nitrogen Puzzle in the Oceans

05.11.2013
Nitrogen isotope effects by anammox deciphered.

A team of scientists from the Max Planck Institute for Marine Microbiology, the University of Basel, and Radboud University Nijmegen has now revealed the details of an important microbial process regulating the global nitrogen budget in the oceans. They present their results in the Proceedings of the National Academy of Sciences of the United States of America.


Schematic view of nitrogen net gain and loss in the ocean. Max Planck Institute for Marine Microbiology


Bioreactor with anammox enrichment culture.
Boran Kartal, Radboud University Nijmegen

Every organism needs nitrogen to survive and grow

Many organisms do not have the ability to obtain nitrogen from molecular nitrogen (N2), the major component in the atmosphere. They do not have the nitrogen fixation pathway – and have to rely on supply of nitrogen that has been fixed by others. The availability of fixed nitrogen, in the form of ammonium, nitrite and nitrate, consequently often limits primary production in the environment (one of the reasons why many fertilizers are rich in fixed nitrogen).

However, there are microbial processes that convert fixed nitrogen back to N2 (production of energy instead of growth). Scientists call this process loss of fixed nitrogen, because it removes the important fixed nitrogen from the environment, and thereby limits primary productivity (i.e. production of biomass). These nitrogen-loss processes, which are carried out by different types of microbes, include the reduction of nitrogen compounds like nitrate and nitrite, the oxidation of ammonium, and a process that combines nitrite and ammonium to form N2, the anaerobic ammonium oxidation (anammox).

In the water column of the ocean, these nitrogen-loss processes are most prominent in water bodies, known as oxygen minimum zones (OMZs), where dissolved oxygen (O2) is rapidly consumed almost to completion. There is major concern that such OMZs will expand in the future due to climate change, which could have a massive impact on the amount of nitrogen lost from the marine realm, affecting the primary productivity in the ocean.

For these reasons, it is important to know which microbial process is responsible for what part of the observed nitrogen-loss, and where this process happens within OMZs.

Found: The missing piece to solve the N isotope puzzle

Prof. Dr. Ben Brunner, one of the three main authors, explains: “We can answer this question with the help of stable nitrogen isotopes, by looking at the ratio between the stable isotopes 15N and 14N in the different pools of fixed N and in the produced N2, because different microbial processes leave different N isotope fingerprints; some prefer the light isotope 14N over the heavier isotope 15N, and others do the opposite.” Dr. Sergio Contreras, a (paleo) biogeochemist interested in the past and future of the Nitrogen cycling, continues: “However, the prerequisite to decipher the N isotope signatures in the environment is to know the isotope fingerprint of the individual nitrogen-loss processes”. Prof. Dr. Moritz Lehmann, isotope biogeochemist from the University of Basel, adds: “ This is where so far, there was a gaping hole in our knowledge. The isotope effects of one major N-loss process, namely anammox, were unknown, and previous N-isotope based assessments of fixed N loss rates in the global ocean may have been severely biased.”

Dr. Boran Kartal, microbiologist at Radboud University Nijmegen, explains: “We used the highly enriched cultures that are available in our laboratory to determine the nitrogen isotope effects of anammox bacteria. Our findings show that the isotope effects induced by anammox can explain isotope signatures observed in the OMZs, which are very important primary production sites in the oceans.”

Prof. Dr. Marcel Kuypers, director at the Max Planck Institute, summarizes: “This missing piece of information is of utmost importance to solve the nitrogen isotope puzzle, not only because anammox is an important process in OMZs, but also because anammox simultaneously affects the nitrogen isotope composition of all nitrogen pools of interest: it converts ammonium and nitrite to N2 and nitrate.”

Through their joint effort the scientists were able to decipher the intricate isotope fingerprint of anammox. Their results, published in the Proceeding of the National Academy of Sciences of the United States of America, reconcile so far mysterious N isotope patterns from OMZ, and provide the missing piece to solve the nitrogen isotope puzzle for fixed N-loss from the environment.

Further Information
Prof. Dr. Marcel Kuypers, +49 421 2028602, mkuypers@mpi-bremen.de
Prof. Dr. Ben Brunner, +45 871 56586, benobru@gmail.com
Dr. Gaute Lavik, +49 421 2028651, glavik@mpi-bremen.de
Prof. Dr. Moritz Lehmann, moritz.lehmann@unibas.ch
Dr. ir. Boran Kartal kartal@science.ru.nl
Press officer
Dr. Manfred Schloesser, +49 421 2028704, mschloes@mpi-bremen.de
Original publication
Nitrogen isotope effects induced by anammox bacteria
B. Brunner, S. Contreras, M.F. Lehmann, O. Matantseva, M. Rollog, T. Kalvelage, G. Klockgether, G. Lavik, M.S.M. Jetten, B. Kartal and M.M.M. Kuypers (2013)

Proc. Natl. Acad. Sci. USA, doi 10.1073/pnas.1310488110

Institutes and Universities
Max Planck Institute for Marine Microbiology, Department of Biogeochemistry, Celsiusstrasse 1, D-28359 Bremen, Germany
Departement Umweltwissenschaften (Biogeochemie), Universität Basel, Bernoullistrasse 30, 4056 Basel, Switzerland

Institute of Water and Wetland Research, Department of Microbiology, Radboud University Nijmegen, Heyendaelseweg 135, 6525 AJ Nijmegen, The Netherlands

Weitere Informationen:

http://www.mpi-bremen.de
Homeopage Max Planck Institute for Marine Microbiology

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

More articles from Life Sciences:

nachricht Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?
26.05.2017 | Paul-Ehrlich-Institut - Bundesinstitut für Impfstoffe und biomedizinische Arzneimittel

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>