Letters to Nature

Nature 407, 623-626 (5 October 2000) | doi:10.1038/35036572; Received 16 May 2000; Accepted 1 August 2000

A marine microbial consortium apparently mediating anaerobic oxidation of methane

Antje Boetius1, Katrin Ravenschlag1, Carsten J. Schubert1, Dirk Rickert2, Friedrich Widdel1, Armin Gieseke1, Rudolf Amann1, Bo Barker Jørgensen1, Ursula Witte1 & Olaf Pfannkuche2

  1. Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany
  2. GEOMAR Research Center for Marine Geosciences, 24148 Kiel, Germany

Correspondence to: Antje Boetius1 Correspondence and requests for materials should be addressed to A.B. (e-mail: Email: aboetius@mpi-bremen.de).

A large fraction of globally produced methane is converted to CO2 by anaerobic oxidation in marine sediments1. Strong geochemical evidence for net methane consumption in anoxic sediments is based on methane profiles2, radiotracer experiments3 and stable carbon isotope data4. But the elusive microorganisms mediating this reaction have not yet been isolated, and the pathway of anaerobic oxidation of methane is insufficiently understood. Recent data suggest that certain archaea reverse the process of methanogenesis by interaction with sulphate-reducing bacteria5, 6, 7. Here we provide microscopic evidence for a structured consortium of archaea and sulphate-reducing bacteria, which we identified by fluorescence in situ hybridization using specific 16S rRNA-targeted oligonucleotide probes. In this example of a structured archaeal-bacterial symbiosis, the archaea grow in dense aggregates of about 100 cells and are surrounded by sulphate-reducing bacteria. These aggregates were abundant in gas-hydrate-rich sediments with extremely high rates of methane-based sulphate reduction, and apparently mediate anaerobic oxidation of methane.