Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Aerobic processes compete for nitrogen in oxygen minimum zones

06.09.2016

At the margins of oxygen minimum zones (OMZs) at ultralow oxygen concentrations, aerobic ammonium and nitrite oxidizers compete for nitrogen with anaerobic microorganisms. Thus they play an important but so far overlooked role in controlling nitrogen loss in OMZs.

An international group of researchers including Laura Bristow from the Max Planck Institute for Marine Microbiology in Bremen unveiled a surprising feature in the oceanic nitrogen cycle. The researchers were working in oxygen minimum zones (OMZs), which are hot spots in the nitrogen cycle. OMZs are areas in the ocean that contain very little or no oxygen. They are a natural phenomenon, but might be expanding due to anthropogenic influence.


Methodically, this was pioneering work: Without highly-sensitive oxygen sensorsit would not have been possible. The developers of the so-called STOX sensors supported Bristow in this study.

Laura Tiano

Bristow and colleagues discovered that tiny amounts of oxygen are sufficient to drive processes that typically occur in more oxygenated waters. These processes are ammonium oxidation and nitrite oxidation (AmOx and NitOx).

“If only a smidgen of oxygen was present, the ammonium and nitrite oxidizers instantly take advantage”, Bristow says. At the fringes of OMZs and during sporadic intrusions of oxygen, AmOx and NitOx can become very important. They are able to use the few available oxygen molecules around them and oxidize nitrogen. The microorganisms from the OMZ miss out. As a consequence, much less nitrogen is available for anaerobic processes such as anammox and denitrification.

This is important for the nitrogen cycle as, for example, anammox bacteria are very active in OMZs, where they transform nitrogen compounds to unreactive N2 gas. The ammonium and nitrite oxidizers, however, keep the nitrogen in an available form. Their activity at ultralow oxygen concentrations thus influences nitrogen cycling in the ocean, which itself has a major influence on the marine carbon cycle.

„We never had the technology before to look at AmOx and NitOx at the relevant oxygen concentrations”, says Bristow, explaining the motivation for this study. “We wanted to know how much these “aerobic” processes overlapped with “anaerobic” processes in OMZs and investigate their potential to control nitrogen loss”. Now Bristow and colleagues clearly show: AmOx und NitOx have an exceptionally high affinity for oxygen.

„Next we need to include AmOX and NitOx in our OMZ models”, Bristow looks into the future. First, the scientists want to take a closer look at the involved organisms. „I hope that more of these organisms will either be isolated, or that we can gain more data about them using molecular techniques. Both would allow us to further investigate how they function.”

Additional information:
As an essential nutrient, nitrogen plays a critical role in regulating oceanic primary productivity. Microorganisms cause nitrogen to be cycled between many different forms (ammonium, nitrate, nitrite, N2 gas). Some forms of nitrogen are available to organisms, others aren’t and a number of these transformations can only occur when oxygen is present. It’s a complex puzzle, not all parts of which are understood to date.

Original publication
Ammonium and nitrite oxidation at nanomolar oxygen concentrations in oxygen minimum zone waters. Laura A. Bristow, Tage Dalsgaard, Laura Tiano, Daniel B. Mills, Anthony Bertagnolli, Jody J. Wright, 
Steven J. Hallam, Osvaldo Ulloa, Donald E. Canfield, Niels Peter Revsbech and Bo Thamdrup. PNAS. 


Participating institutes
Max Planck Institute for Marine Microbiology, Bremen, Germany
University of Southern Denmark, Odense, Denmark
Aarhus University, Aarhus, Denmark
Universidad de Concepción, Casilla, Concepción, Chile
University of British Columbia, Vancouver, Canada

Weitere Informationen:

http://www.mpi-bremen.de

Dr. Fanni Aspetsberger | Max-Planck-Institut für marine Mikrobiologie

More articles from Life Sciences:

nachricht Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>