Publication Date:
2016-04-18
Description:
the emission of gas from seabed reservoirs. The microorganisms
inhabiting methane seeps transform the chemical energy in
methane to products that sustain rich benthic communities around
the gas leaks. Despite the biogeochemical relevance of microbial
methane removal at seeps, the global diversity and dispersion
of seep microbiota remain unknown. Here we determined the
microbial diversity and community structure of 23 globally distributed
methane seeps and compared these to the microbial communities
of 54 other seafloor ecosystems, including sulfate–methane
transition zones, hydrothermal vents, coastal sediments, and deepsea
surface and subsurface sediments. We found that methane
seep communities show moderate levels of microbial richness compared
with other seafloor ecosystems and harbor distinct bacterial
and archaeal taxa with cosmopolitan distribution and key biogeochemical
functions. The high relative sequence abundance of ANME
(anaerobic methanotrophic archaea), as well as aerobic Methylococcales,
sulfate-reducing Desulfobacterales, and sulfide-oxidizing
Thiotrichales, matches the most favorable microbial metabolisms at
methane seeps in terms of substrate supply and distinguishes the
seep microbiome from other seafloor microbiomes. The key functional
taxa varied in relative sequence abundance between different
seeps due to the environmental factors, sediment depth and seafloor
temperature. The degree of endemism of the methane seep microbiome
suggests a high local diversification in these heterogeneous
but long-lived ecosystems. Our results indicate that the seep microbiome
is structured according to metacommunity processes and that
few cosmopolitan microbial taxa mediate the bulk of methane
oxidation, with global relevance to methane emission in the ocean.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
peerRev
,
info:eu-repo/semantics/article
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