Aquatic Sciences Meeting, Albuquerque 2001

SS14 Microbial Diversity (Disciplinary Connections)

Date: Tuesday, February 13, 2001, Time: 9:45:00 AM

Location: Mesilla

Teske, A, P, Woods Hole Oceanographic Institution, Woods Hole, USA, ateske@whoi.edu

Gomez, A, V, Woods Hole Oceanographic Institution, Woods Hole, USA,

Edgcomb, V, P, Marine Biological Laboratory, Woods Hole, USA,

Kysela, D, , Marine Biological Laboratory, Woods Hole, USA,

Hinrichs, K, U, Woods Hole Oceanographic Institution, Woods Hole, USA,

NOVEL ARCHAEA IN GUAYMAS BASIN HYDROTHERMAL VENT SEDIMENTS: EVIDENCE FOR ANAEROBIC METHANOTROPHY

Phylogenetic composition and carbon isotopic signatures of microbial communities in hydrothermal sediments of the Guaymas Basin (Gulf of California, Mexico) were analyzed by 16S rRNA sequencing and by C-13 isotopic analysis of archaeal and bacterial lipids. The Guaymas sediments contained two major lineages of methanogen-related, uncultured archaea (ANME-1 and ANME-2 cluster) and a cluster of uncultured species related to the Methanosarcinales, the acetoclastic methanogens. Predominant archaeal lipids in the Guaymas Basin sediments included archaeol and sn-2-hydroxyarchaeol, diagnostic for non-thermophilic euryarchaota and members of the Methanosarcinales. These lipids were extremely C-13 depleted (delta C-13 minus 60 to 80 permil), indicating that they originated from the microbial assimilation and oxidation of C-13 depleted biogenic methane. Matching sequence profiles and lipid signatures together identify anaerobic methane-oxidizing archaeal community members. They occur associated with diverse bacterial populations, including Delta- and epsilon-Proteobacteria, green non-sulfur bacteria, and the uncultured candidate subdivision OP11. Bacterial consumers of anaerobic methane oxidation products (acetate and/or hydrogen) would make this process thermodynamically feasible.

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Aquatic Sciences Meeting, Albuquerque 2001

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