Navigation Links
Bacteria forge nitrogen from nitric oxide
Date:10/5/2011

This release is available in German.

The anaerobic oxidation of ammonia (anammox) is an important pathway in the nitrogen cycle that was only discovered in the 1980s. Currently, scientists estimate that about 50 percent of the nitrogen in the atmosphere is forged by this process. A group of specialized bacteria perform the anammox reaction, but so far scientists have been in the dark about how these bacteria could convert ammonia to nitrogen in the complete absence of oxygen. Now, 25 years after its discovery, they finally solved the molecular mechanism of anammox.

Anammox bacteria are very unusual because they contain an organelle which is a typical eukaryotic feature. Inside this organelle, known as the "anammoxosome", the bacteria perform the anammox reaction. The membrane of the anammoxosome presumably protects the cells from highly reactive intermediates of the anammox reaction. These intermediates could be hydrazine and hydroxylamine, as microbiologists proposed many years ago. This was very exciting news because the turnover of hydrazine, a very powerful reductant also used as rocket fuel, had never been shown in biology. However, these early experiments were provisional and many open questions remained.

To finally unravel the pathway experimentally was a very difficult enterprise. Marc Strous from the Max Planck Institute in Bremen says: "The anammox organisms are difficult to cultivate because they divide only once every two weeks. Therefore we had to develop cultivation approaches suitable for such low growth rates. Even after 20 years of trials, we can still only grow the organisms in bioreactors and not in pure culture." In the present study, the researchers make use of the latest innovation in bioreactor technology for anammox cultivation: the membrane bioreactor. In such bioreactors the anammox organisms grow as suspended cells rather than in biofilms on surfaces, and relatively few contaminating organisms are present. The study makes use of protein purification and proteins cannot be effectively purified from biofilms because of the large amount of slime associated with these biofilms.

Another important key to the metabolism was the availability of the genome sequence of one of the best known anammox bacteria, Kuenenia stuttgartiensis. With the knowledge of the genome, the authors knew which proteins could be important. Based on the genome sequence, they could predict that nitric oxide, not hydroxylamine, might be the precursor for hydrazine. With a set of state-of-the art molecular methods the scientists could thus completely unravel the anammox pathway, and unequivocally establish the role of hydrazine and nitric oxide (NO) as intermediates.

"With this significant advance we can finally understand how the nitrogen in the air we breathe is created: from rocket fuel and nitric oxide!" concludes Marc Strous. With the establishment of the prominent role of nitric oxide in both anammox and denitrification, the research also opens a new window on the evolution of the biological nitrogen cycle in the Earth's distant past. Marc Strous explains: "In the early days in Earth's history, the nitric oxide accumulated in the atmosphere by vulcanic activity, was presumably the first "deep electron sink" on earth and may so have enabled the evolution of both microbial metabolic pathways anammox and denitrification."


'/>"/>

Contact: Marc Strous
mstrous@mpi-bremen.de
49-421-202-8822
Max-Planck-Gesellschaft
Source:Eurekalert  

Related biology news :

1. Disinfectants can make bacteria resistant to treatment
2. H. Pylori bacteria may help prevent some esophageal cancers
3. Scientists discover bacteria that can cause bone infections
4. Waste from gut bacteria helps host control weight, UT Southwestern researchers report
5. Gene against bacterial attack unravelled
6. Predatory bacterial swarm uses rippling motion to reach prey
7. Bacteria manage perfume oil production from grass
8. Nature study demonstrates that bacterial clotting depends on clustering
9. Battling bacteria in the blood: Researchers tackle deadly infections
10. Shifts in soil bacterial populations linked to wetland restoration success
11. New bacteria discovered in raw milk
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Bacteria forge nitrogen from nitric oxide
(Date:3/2/2017)... Australian stem cell and regenerative medicine company, ... an agreement with the Monash Lung Biology Network, a ... and Department of Pharmacology at Monash University, ... to support the use of Cymerus™ mesenchymal stem cells ... Asthma is a chronic, long term lung condition recognised ...
(Date:2/28/2017)... 28, 2017 News solutions for biometrics, bag ... ... from 14 to 16 March, Materna will present its complete ... seamless travel is a real benefit for passengers. To accelerate ... their passenger touch point solutions to take passengers through the complete ...
(Date:2/26/2017)... Feb. 25, 2017  Securus Technologies, a leading ... for public safety, investigation, corrections and monitoring, announces ... Reentry. "Too often, too many offenders ... county jails are trying to tackle this ongoing ... friends and family members. While significant steps are underway, ...
Breaking Biology News(10 mins):
(Date:3/22/2017)... , ... March 21, 2017 , ... Okyanos Cell Therapy ... as part of their live events series, “Stem Cell Therapy: The Next Phase in ... under the 2013 Stem Cell Research and Therapy Act, Okyanos maintains a ...
(Date:3/22/2017)... ... March 21, 2017 , ... Benchworks CEO Thad L. Bench ... on March 23-24 in San Diego. The event is a gathering of executive ... , Benchworks Vice President Christian Meyer will also participate in the forum. Participants will ...
(Date:3/22/2017)... York, NY (PRWEB) , ... March 21, 2017 , ... ... Officer Summit (CMO Summit) to be held on May 10-11, 2017, at the ... in the country specifically for Chief Medical Officer peer-to-peer learning, benchmarking and support. , ...
(Date:3/22/2017)... (PRWEB) , ... March 21, 2017 , ... Functional near-infrared ... oxygenation, is being explored as a way to track the brain’s response to acute ... pain activation by cold pressor test ,” published today in the journal Neurophotonics ...
Breaking Biology Technology: