Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microbes can grow on nitric oxide (NO)

18.03.2019

Nitric oxide (NO) is a central molecule of the global nitrogen cycle. A study by Boran Kartal from the Max Planck Institute for Marine Microbiology, Germany, and colleagues reveals that microorganisms can grow on NO. Their results, which are now published in Nature Communications, change our view of the earth’s nitrogen cycle and how microorganisms regulate the release of greenhouse gases from natural and man-made environments.

Nitric oxide is a fascinating and versatile molecule, important for all living things as well as our environment: It is highly reactive and toxic, it is used as a signaling molecule, it depletes the ozone layer in our planet’s atmosphere and it is the precursor of the greenhouse gas nitrous oxide (N2O).


One of the bioreactors that Kartal and colleagues used to grow cells of K. stuttgartiensis. The bright red color is due to the presence of iron-containing cytochrome c proteins in the cells.

Boran Kartal


Kuenenia stuttgartiensis, here seen under a transmission electron microscope, is a model anammox microorganism, which grows as single cells.

Laura van Niftrik

Nitrogen oxides are also pollutants discharged with exhaust gases, for example from combustion engines in cars, and are harmful to human health.

Intriguingly, long before there was oxygen on Earth, nitric oxide was available as a high-energy oxidant, and might have played a fundamental role in the emergence and evolution of life on Earth.

A study by Max-Planck-scientist Boran Kartal and colleagues now published in Nature Communications sheds a new light on microbial transformations of this molecule.

Yes they can – with implications for our climate

One major question about nitric oxide remained unanswered up to now: Can organisms use it to grow? “One would think so,” Kartal explains, “as nitric oxide has been around since the emergence of life on earth.”

However, no microbe growing on NO has been found - until now. Kartal and his colleagues from Radboud University in the Netherlands have now discovered that the anaerobic ammonium-oxidizing (anammox*) bacteria directly use NO to grow. In detail, these microorganisms couple ammonium oxidation to NO reduction, producing nothing but dinitrogen gas (N2) in the process.

The latter – the sole production of N2 – is particularly intriguing: Some microbes convert NO to nitrous oxide (N2O), which is a potent greenhouse gas. N2, in contrast, is harmless. Thus, each molecule of NO that is transformed into N2 instead of N2O is one less molecule adding to climate change.

“In this way, anammox bacteria reduce the amount of NO available for N2O production, and reduce the amount of released greenhouse gas”, Kartal explains.

“Our work is interesting in understanding how anammox bacteria can regulate N2O and NO emissions from natural and man-made ecosystems, such as wastewater treatment plants, where these microorganisms contribute significantly to N2-release to the atmosphere.”

Rethinking the nitrogen cycle

Nitric oxide is a central molecule in the global cycling of nitrogen. “These findings change our understanding of the earth’s nitrogen cycle. Nitric oxide has been primarily thought of as a toxin, but now we show that anammox bacteria can make a living from converting NO to N2”, says Kartal. The present study raises new questions.

“Anammox, a globally important microbial process of the nitrogen cycle relevant for the earth’s climate, does not work the way we assumed it did.” Moreover, other microbes than the ones investigated here could be using NO directly as well. Anammox bacteria are found all over the planet. “In this sense, the anammox microbes growing on nitric oxide could also be basically everywhere”, Kartal continues.

One answer, many new questions

Now, Kartal and his group at Max Planck Institute in Bremen are exploring different ecosystems from all around the world, hunting for specialized nitric oxide converting microorganisms.

They want to understand better how microbes use NO in environments both with and without oxygen. This will probably pave the way to the discovery of new enzymes involved in nitric oxide transformation. “Basically, we want to understand how organisms can make a living on NO.”


* What is anammox?

Anammox, short for anaerobic ammonium oxidation, is a globally important microbial process of the nitrogen cycle. It takes place in many natural and man-made environments. In the process, nitrite and ammonium ions are converted directly into dinitrogen and water and nitrate.

Anammox is responsible for approximately 50% of the N2 gas produced in the oceans. It thus removes large amounts of bioavailable nitrogen from the seas. This nutrient nitrogen is then no longer available to other organisms; this way anammox can control oceanic primary productivity.

The anammox process is also of interest in wastewater treatment. Removing nitrogen compounds with the help of anammox bacteria is significantly cheaper than traditional methods and reduces emissions of the greenhouse gas CO2.

Wissenschaftliche Ansprechpartner:

Dr. Boran Kartal
Head of the Microbial Physiology Group
Max Planck Institute for Marine Microbiology,
Bremen, Germany
Phone: +49 421 2028-645
E-Mail: bkartal@mpi-bremen.de

Dr. Fanni Aspetsberger
Press officer
Max Planck Institute for Marine Microbiology,
Bremen, Germany
Phone: +49 421 2028-947
E-Mail: faspetsb@mpi-bremen.de

Originalpublikation:

Ziye Hu, Hans JCT Wessels, Theo van Alen, Mike SM Jetten and Boran Kartal: Nitric oxide-dependent anaerobic ammonium oxidation. Nature Communications. DOI: 10.1038/s41467-019-09268-w


Be­tei­lig­te In­sti­tu­te:

Max-Planck-Institut für Marine Mikrobiologie, Bremen, Deutschland
Radboud Universität, Nijmegen, Niederlande

Weitere Informationen:

https://www.mpi-bremen.de/Page3494.html

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

More articles from Life Sciences:

nachricht If Machines Could Smell ...
19.07.2019 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Algae-killing viruses spur nutrient recycling in oceans
18.07.2019 | Rutgers University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Better thermal conductivity by adjusting the arrangement of atoms

Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.

In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...

Im Focus: First-ever visualizations of electrical gating effects on electronic structure

Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.

Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

Im Focus: Extremely hard yet metallically conductive: Bayreuth researchers develop novel material with high-tech prospects

An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".

The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

Heat flow through single molecules detected

19.07.2019 | Physics and Astronomy

Heat transport through single molecules

19.07.2019 | Physics and Astronomy

Welcome Committee for Comets

19.07.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>