Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 12, issue 15
Biogeosciences, 12, 4725-4737, 2015
https://doi.org/10.5194/bg-12-4725-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Biogeosciences, 12, 4725-4737, 2015
https://doi.org/10.5194/bg-12-4725-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 06 Aug 2015

Research article | 06 Aug 2015

Intact polar lipids of Thaumarchaeota and anammox bacteria as indicators of N cycling in the eastern tropical North Pacific oxygen-deficient zone

M. Sollai1, E. C. Hopmans1, S. Schouten1,3, R. G. Keil2, and J. S. Sinninghe Damsté1,3 M. Sollai et al.
  • 1NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, P.O. Box 59, 179AB Den Burg, the Netherlands
  • 2School of Oceanography, University of Washington, Box 355351, Seattle, Washington, 98195-5351, USA
  • 3University of Utrecht, Faculty of Geosciences, P.O. Box 80.021, 3508 TA Utrecht, the Netherlands

Abstract. In the last decade our understanding of the marine nitrogen cycle has improved considerably thanks to the discovery of two novel groups of microorganisms: ammonia-oxidizing archaea (AOA) and anaerobic ammonia-oxidizing (anammox) bacteria. Both groups are important in oxygen-deficient zones (ODZs), where they substantially affect the marine N budget. These two groups of microbes are also well known for producing specific membrane lipids, which can be used as biomarkers to trace their presence in the environment. We investigated the occurrence and distribution of AOA and anammox bacteria in the water column of the eastern tropical North Pacific (ETNP) ODZ, one of the most prominent ODZs worldwide. Suspended particulate matter (SPM) was collected at different depths of the water column in high resolution, at both a coastal and an open-ocean setting. The SPM was analyzed for AOA- and anammox bacteria-specific intact polar lipids (IPLs), i.e., hexose-phosphohexose (HPH)-crenarchaeol and phosphatidylcholine (PC)-monoether ladderane. Comparison with oxygen profiles reveals that both the microbial groups are able to thrive at low (< 1 μM) concentrations of oxygen. Our results indicate a clear niche segregation of AOA and anammox bacteria in the coastal waters of the ETNP but a partial overlap of the two niches of these microbial species in the open-water setting. The latter distribution suggests the potential for an interaction between the two microbial groups at the open-ocean site, although the nature of this hypothetical interaction (i.e., either competition or cooperation) remains unclear.

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The distribution of Thaumarchaeota and anammox bacteria in the water column of the eastern tropical North Pacific (ETNP) oxygen-deficient zone (ODZ) was investigated by collecting suspended particulate matter (SPM) and analyzing it for the content of specific intact polar lipids (IPLs) produced by the two microbial groups. We found a clear niche segregation in the distribution of the two groups in the coastal waters of the ETNP but a partial overlap of their niches in the open-water setting.
The distribution of Thaumarchaeota and anammox bacteria in the water column of the eastern...
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