Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




WATER WORLD
The nitrogen puzzle in the oceans
by Staff Writers
Basel, Germany (SPX) Nov 06, 2013


This is a bioreactor with anammox enrichment culture. Credit: Boran Kartal, Radboud University Nijmegen.

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.

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.

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."

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".

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."

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."

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.

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

.


Related Links
Max-Planck-Gesellschaft
Water News - Science, Technology and Politics






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





WATER WORLD
Faroe Islands launches fish fight with EU at WTO
Geneva (AFP) Nov 04, 2013
The Faroe Islands Monday fired the first shot in what looks set to be an all-out trade battle at the World Trade Organization over EU trade sanctions on its fish. The WTO said that the northern Atlantic territory, located between Norway and Iceland, had made a formal request for consultations with the European Union over measures that restrict the entry of herring and mackerel caught under t ... read more


WATER WORLD
Shanghai-built lunar rover set for lunar landing

Crowdfunded Lunar Spacecraft Reaches Funding Milestone

LADEE Continues To Settle Into Operational Lunar Orbit

NASA's moon landing remembered as a promise of a 'future which never happened'

WATER WORLD
India reaches for Mars on prestige space mission

India mission to Mars blasts off successfully

Mars Mission: India's Tryst with the Red Planet

Martian box of delights

WATER WORLD
From North Pole to the stars: Russia's thrill-seeking tycoon

A look at recent tech sector IPOs

NASA's Orion Spacecraft Comes to Life

Flights of Fancy

WATER WORLD
China shows off moon rover model before space launch

China providing space training

China launches experimental satellite Shijian-16

China Moon Rover A New Opportunity To Explore Our Nearest Neighbor

WATER WORLD
Spaceflight Joins with NanoRacks to Deploy Satellites from the ISS

Crew Completes Preparations for Soyuz Move

Mission accomplished for Europe's cargo freighter

Soyuz changes parking spots at space station, making way for new crew

WATER WORLD
Kazakhstan say Baikonur launch site may be open to Western countries

ESA Swarm launch postponed

Europe's fifth ATV for launch by Arianespace begins its pre-flight checkout at the Spaceport

ILS Proton Launches Sirius FM-6 Satellite

WATER WORLD
NASA Kepler Results Usher in a New Era of Astronomy

Astronomers answer key question: How common are habitable planets?

One in five Sun-like stars may have Earth-like planets

Mystery World Baffles Astronomers

WATER WORLD
Breakthrough in study of aluminum should yield new technological advances

Gravity and the robot satellite attitude problem

Global IT spending set to recover in 2014

Plasmonic crystal alters to match light-frequency source




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement