Klawonn, Isabell; Eichner, Meri; Wilson, Samuel T; Moradi, Nasrollah; Thamdrup, Bo; Kümmel, Steffen; Gehre, Matthias; Khalili, Arzhang; Grossart, Hans-Peter; Karl, Dave; Ploug, Helle (2019): Microsensor measurements of oxygen concentration profiles, and computer-simulated concentration profiles of oxygen, ammonium and nitrate oxygen in Trichodesmium colonies [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.907637, Supplement to: Klawonn, Isabell; Eichner, Meri J; Wilson, Samuel T; Moradi, Nasrollah; Thamdrup, Bo; Kümmel, Steffen; Gehre, Matthias; Khalili, Arzhang; Grossart, Hans-Peter; Karl, David Michael; Ploug, Helle (2020): Distinct nitrogen cycling and steep chemical gradients in Trichodesmium colonies. The ISME Journal, 14(2), 399-412, https://doi.org/10.1038/s41396-019-0514-9
Always quote citation above when using data! You can download the citation in several formats below.
Published: 2019-10-18 • DOI registered: 2019-12-14
Abstract:
Trichodesmium is an important dinitrogen (N~2~)-fixing cyanobacterium in marine ecosystems. Recent nucleic acid analyses indicate that Trichodesmium colonies with their diverse epibionts support various nitrogen (N) transformations beyond N~2~-fixation. However, rates of these transformations and concentration gradients of N-compounds in Trichodesmium colonies remain largely unresolved. We combined isotope-tracer incubations, micro-profiling, and numeric modelling to explore carbon fixation, N-cycling processes, as well as oxygen, ammonium and nitrate concentration gradients in individual field-sampled Trichodesmium colonies. Colonies were net-autotrophic, with carbon and N~2~-fixation occurring mostly at day-time. Ten percent of the fixed N was released as ammonium after 12-hour incubations. Nitrification was not detectable but nitrate consumption was high when nitrate was added. The consumed nitrate was partly reduced to ammonium, while denitrification was insignificant. Thus, the potential N-transformation network was characterized by fixed N gain and recycling processes rather than denitrification. Oxygen concentrations within colonies were 60–200% air-saturation. Moreover, our modelling predicted steep concentration gradients, with up to 6-fold higher ammonium concentrations, and nitrate depletion in the colony centre compared to the ambient seawater. These gradients created a chemically heterogeneous microenvironment, presumably facilitating diverse microbial metabolisms in millimetre-sized Trichodesmium colonies.
Comment:
The dataset includes measurements of oxygen profiles in Trichodesmium colonies, and modelled profiles and concentration fields of oxygen, ammonium and nitrate. The data included are plotted in Figure 3 and 4 in the indicated original article.
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | File name | File name | Klawonn, Isabell | |||
| 2 | File format | File format | Klawonn, Isabell | |||
| 3 | File size | File size | kByte | Klawonn, Isabell | ||
| 4 | Uniform resource locator/link to file | URL file | Klawonn, Isabell |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0)
Size:
12 data points