Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Scientists unravel the mystery of marine methane oxidation

13.11.2012
Researchers uncover how microorganisms on the ocean floor protect the atmosphere against methane

Microbiologists and geochemists from the Max Planck Institute for Marine Microbiology, along with their colleagues from Vienna and Mainz, show that marine methane oxidation coupled to sulfate respiration can be performed by a single microorganism, a member of the ancient kingdom of the Archaea, and does not need to be carried out in collaboration with a bacterium, as previously thought. They published their discovery as an article in the renowned scientific journal Nature.


The enrichment of the microorganisms responsible for marine AOM, archaea in red and bacteria in green from the Isis Mud Volcano in the Mediterranean Sea has taken 8 years of continuous incubation. Without these cultures it would not have been possible to trace down the complex sulfur cycling involved in AOM.

© Jana Milucka, MPI f. Marine Microbiology


In this model, methane oxidation and sulfate respiration to elemental sulfur (or all the way to sulfide) is performed by the methanotrophic archaea (ANME). The associated bacteria (DSS) are disproportionators (sulfur fermentors), which take up produced elemental sulfur in the form of disulfide and turn it into sulfate and sulfide. Dark circles represent iron- and phosphorus-rich precipitates found in the bacteria.

© Jana Milucka, MPI f. Marine Microbiology

Vast amounts of methane are stored under the ocean floor. Anaerobic oxidation of methane coupled to sulfate respiration (AOM) prevents the release of this potent greenhouse gas into the atmosphere. Although the process was discovered 35 years ago it has remained a long standing mystery as to how microorganisms perform this reaction. A decade ago, an important discovery was made which showed that two different microorganisms are often associated with AOM. It was proposed that these two microorganisms perform different parts of the AOM reaction. One, an archaeon, was supposed to oxidize methane and the other, a bacterium, was supposed to respire sulfate. This implied the existence of an intermediate compound to be shuttled from the methane oxidizer to the sulfate respirer.

Now, the team around Professor Kuypers has turned this whole model on its head. They show that the archaeon not only oxidizes methane but can also respire sulfate and does not necessarily need the bacterial partner. It appears that the archaeon does not employ the common enzyme toolbox that other known sulfate-respiring microorganisms use, but relies on a different, unknown pathway.

The basis for this dramatic shift in thinking is the observation that elemental sulfur is formed and accumulates in the methane-oxidizing archaeon. “Using chromatographic and state-of-the-art spectroscopic techniques we found surprisingly high concentrations of elemental sulfur in our cultures”, says Professor Marcel Kuypers and adds: “The single-cell techniques showed that the sulfur content in the methane-degrading archaeon was much higher than in the bacterium. Our experiments show that this sulfur is formed during sulfate respiration.”
This finding begs the question: What does the bacterium do if the archaeon does both sulfate respiration and methane oxidation? “The bacteria actually make a living off of the elemental sulfur produced by the archaea”, explains Jana Milucka, first author of the study. “The bacteria grow by splitting the elemental sulfur into sulfate and hydrogen sulfide. This is a form of fermentation, like the process that produces alcohol.”

“Until now we have always had trouble explaining the occurrence of elemental sulfur in oxygen-free sediments”, notes Tim Ferdelman, scientist at the MPI Bremen and coauthor on the publication. ”Our discoveries not only provide a mechanism for marine methane oxidation but also cast a new light on the carbon and sulfur cycling in marine, methane-rich sediments.”

Contact

Dr. Marcel Kuypers
Max Planck Institute for Marine Microbiology, Bremen
Phone: +49 421 2028-602
Fax: +49 421 2028-690
Email: mkuypers@­mpi-bremen.de
Dr. Rita Dunker
Max Planck Institute for Marine Microbiology, Bremen
Phone: +49 421 2028-856
Fax: +49 421 2028-790
Email: rdunker@­mpi-bremen.de
Dr. Manfred Schlösser
Press Officer
Max Planck Institute for Marine Microbiology, Bremen
Phone: +49 4 212028-704
Email: mschloes@­mpi-bremen.de

Original publication
Jana Milucka, Timothy G. Ferdelman, Lubos Polerecky, Daniela Franzke, Gunter Wegener, Markus Schmid, Ingo Lieberwirth, Michael Wagner, Friedrich Widdel, Marcel M. M. Kuypers
Zerovalent sulfur is a key intermediate in marine methane oxidation
Nature, 2012. 8 November, 2012. Doi: 10.1038/nature11656

Dr. Marcel Kuypers | Max-Planck-Institut
Further information:
http://www.mpg.de/6619070/marine-methane-oxidation

More articles from Life Sciences:

nachricht A 'movie' of ultrafast rotating molecules at a hundred billion per second
06.07.2015 | National Institutes of Natural Sciences

nachricht First Comprehensive Analysis of the Woolly Mammoth Genome Completed
06.07.2015 | University of Chicago Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Windturbinen unter Brücken sind sinnvoll

Ansatz für dicht verbaute oder schützenswerte Gebiete attraktiv

Laut einem spanisch-britischen Forscherteam wäre es sinnvoll, unter großen Brücken Windturbinen zur Stromgewinnung zu verbauen. Denn Modellrechnungen am...

Im Focus: Forschungsschiff Heincke seit 25 Jahren im Dienst der Wissenschaft

Ein Vierteljahrhundert alt, über 900.000 Kilometer (488.842 nautische Meilen) gefahren und trotzdem auf dem neuesten wissenschaftlichen und technischen Stand: Die Indienststellung des Forschungsschiffes Heincke jährt sich am 8. Juli 2015 zum 25. Mal.

Wissenschaftler des Alfred-Wegener-Instituts, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), das die Heincke betreibt, nehmen ebenso regelmäßig an...

Im Focus: Solardächer produzieren Strom für Fahrzeuge

Studentische Industriekooperation zwischen HAW Hamburg und Webasto erarbeitet Ergebnisse für EU-Zertifizierungsprozess von Solardächern zur Verbesserung der Öko-Bilanz von Fahrzeugen.

Unter der Leitung von Dr.-Ing. Volker Skwarek, Professor für technische Informatik an der HAW Hamburg, erarbeiteten sechs Studierende des...

Im Focus: Viaducts with wind turbines, the new renewable energy source

Wind turbines could be installed under some of the biggest bridges on the road network to produce electricity. So it is confirmed by calculations carried out by a European researchers team, that have taken a viaduct in the Canary Islands as a reference. This concept could be applied in heavily built-up territories or natural areas with new constructions limitations.

The Juncal Viaduct, in Gran Canaria, has served as a reference for Spanish and British researchers to verify that the wind blowing between the pillars on this...

Im Focus: Aus alt mach neu - Rohstoffquelle Elektroschrott

Der Markt für Unterhaltungselektronik boomt: Rund 60 Millionen Fernsehgeräte wurden im letzten Jahr in Europa verkauft. Früher oder später werden sie zurückkehren – als Elektroschrott.

Die Recycling-Industrie hat darauf reagiert: Kupfer, Aluminium, Eisen- und Edelmetalle sowie ausgewählte Kunststoffe werden bereits wiederverwertet. Allerdings...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Rheumatologen tagen in Bremen: Fortschritte in der Rheuma-Therapie und neue Impfempfehlungen

06.07.2015 | Veranstaltungen

9. Aachener Technologie- und Innovationsmanagement-Tagung

06.07.2015 | Veranstaltungen

Flurförderzeuge im Zeichen der Zeit

03.07.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Pepper – der empathische Roboter

06.07.2015 | Energie und Elektrotechnik

Erfolgreich: Zement auf Kohlendioxid

06.07.2015 | Geowissenschaften

3 Mio. Euro für Regensburger Forschungsprojekt – Startschuss für Internetkompetenzzentrum Ostbayern

06.07.2015 | Förderungen Preise