http://lod.bco-dmo.org/id/dataset/921657
eng; USA
utf8
dataset
Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
2024-03-08
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Phytoplankton Nitrogen isotope fractionation from the Biological Nitrogen Isotope Fractionation project
2024-03-08
publication
2024-03-08
revision
BCO-DMO Linked Data URI
2024-03-08
creation
http://lod.bco-dmo.org/id/dataset/921657
Julie Granger
University of Connecticut
principalInvestigator
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
publisher
Cite this dataset as: Granger, J. (2024) Phytoplankton Nitrogen isotope fractionation. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2024-03-08 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/921657 [access date]
Nitrogen isotope fractionation for ammonium assimilation by marine phytoplankton Dataset Description: Methods and Sampling: <p><strong>Phytoplankton cultures</strong></p>
<p>Two strains of marine algae, the diatom <em>Thalassiosira weissflogii</em> (actin) and the prasinophyte <em>Tetraselmis</em> sp. were grown in batch cultures in sterile, acid-washed borosilicate glass or polycarbonate bottles using artificial seawater medium in an environmental chamber at 18<sup>0</sup>C, illuminated with fluorescent light (40 <em>μ</em>mol photons m<sup>-2</sup> s<sup>-1</sup> photosynthetically available radiation) on a 12-hour light and 12-hour dark cycle. The artificial seawater medium was prepared from low nutrient Instant Ocean™ salt dissolved in Milli-Q water and filtered through a 47 mm Whatman GF/F glass microfiber filter (0.7 μm nominal pore-size) and sterilized by autoclaving at 100<sup>0</sup>C via Pasteurization cycle in PRIMUS steam sterilizer, then supplemented with filter-sterilized 100 – 250 <em>μ</em>M NH<sub>4</sub><sup>+</sup>, 10 <em>μ</em>M phosphate, 100 <em>μ</em>M silicic acid (only for <em>T. weissflogii</em> cultures), and f/2 trace metals and vitamins (Guillard and Ryther 1962). The batch cultures were initiated from inocula of approximately 1,000 cells mL<sup>-1</sup>, and cell densities monitored daily using Multisizer 4 Beckman Coulter counter. Media subsamples were collected during exponential growth for analyses of NH<sub>4</sub><sup>+</sup> concentration and N isotope ratios. Subsamples were filtered through a 0.45 μm pore-size polyether-sulfone (PES) syringe filters and collected into acid-washed High Density Poly-Ethylene (HDPE) bottles, solution pH adjusted to ca. 4.5 with dilute hydrochloric acid in order to minimize ammonia volatilization during storage, and samples stored at –20<sup>0</sup>C pending analysis. Particulate organic nitrogen (PON) was also sampled during the exponential growth phase by filtering aqueous subsamples onto a pre-combusted 25 mm Whatman GF/F glass microfiber filters (0.7 μm pore-size) and stored in pre-combusted aluminum foils at –20<sup>0</sup>C pending analysis of N isotope ratio analysis. To capture lower NH<sub>4</sub><sup>+</sup> concentrations, short-term NH<sub>4</sub><sup>+</sup> uptake experiments with <em>T. weissflogii</em> and <em>Tetraselmis</em> sp. were conducted. A first set of experiments was conducted with <em>T. weissflogii</em> and <em>Tetraselmis</em> sp. cells in early stationary phase, wherein NH<sub>4</sub><sup>+</sup> was exhausted from the medium. The cells were collected by gentle filtration onto a 5 μm pore-size 47 mm Isopore<sup>TM</sup> polycarbonate membrane filter and resuspended into fresh medium containing ~60 <em>μ</em>M NH<sub>4</sub><sup>+</sup> for <em>T. weissflogii</em> and 20 <em>μ</em>M NH<sub>4</sub><sup>+</sup> for <em>Tetraselmis</em> sp. Aqueous subsamples were collected at regular time intervals until NH<sub>4</sub><sup>+</sup> in the medium was exhausted. A second set of experiments was conducted with N-replete (cells in exponential growth phase) and N-starved cells (cells two days into stationary phase) of <em>T. weissflogii</em> and <em>Tetraselmis</em> sp. Cell cultures were either diluted into fresh medium containing ~20 µM NH<sub>4</sub><sup>+</sup>, or gently filtered onto a polycarbonate membrane filter and resuspended into said medium. Short-term incubations occurred largely under constant illumination, although some <em>Tetraselmis</em> sp. uptake experiments were inadvertently subject to light-dark conditions.</p>
<p><strong>Determination of NH<sub>4</sub><sup>+</sup> concentration</strong></p>
<p>Ammonium concentrations at or above 50 <em>μ</em>M were measured fluorometrically following derivatization with o-phthalaldehyde (OPA; Holmes et al. 1999) while concentrations &lt; 50 μM were analyzed with the indophenol method (Solórzano 1969).</p>
<p><strong>Analyses of N isotopes of NH<sub>4</sub><sup>+</sup> and PON</strong></p>
<p>Ammonium samples were diluted to 5 µM or 1 µM with deep Atlantic seawater and N isotope ratios determined using the hypobromite-azide method (Zhang et al. 2007), wherein NH<sub>4</sub><sup>+</sup> is first oxidized to nitrite by hypobromite, after which nitrite is converted to a nitrous oxide gas analyte by reacting with azide. The N isotopic composition of the nitrous oxide product was analyzed using a continuous flow purge and dual cryogenic trap system coupled to a custom-modified Gas Bench II device interfaced with a Thermo Delta V gas chromatograph isotope ratio mass spectrometer (GC-IRMS; see Casciotti et al. 2002; McIlvin and Casciotti 2011). Calibration to reference (dinitrogen gas in air) was achieved from parallel reactions of NH<sub>4</sub><sup>+</sup> reference materials IAEA-N1 and IAEA-N2 diluted in deep Atlantic seawater (5 µM or 1 µM solutions), with respective assigned δ<sup>15</sup>N values of 0.43‰ and 20.3‰ vs. air (Böhlke et al. 1993). To analyze N isotopes of PON, frozen glass microfiber filters were lyophilized for 24 hours using an Edwards Super Modulyo freeze-dryer. The filters were packed into tin capsules and analyzed by combustion to dinitrogen gas on a Costech ECS 4010 Elemental Analyzer followed by N isotope ratio analysis of the resulting dinitrogen gas on a Thermo Delta V isotope ratio mass spectrometer. Samples were calibrated with corresponding aliquots of L-glutamic acid reference materials USGS-40 and USGS-41, with δ<sup>15</sup>N values of –4.52 and 47.57‰ vs. air, respectively (Qi et al. 2003).</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1554474 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1554474
onGoing
Julie Granger
University of Connecticut
860-405-9094
Department of Marine Sciences 1080 Shenecossett Road
Groton
CT
06340
USA
julie.granger@uconn.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Multisizer 4 Beckman Coulter Counter
Costech ECS 4010 Elemental Analyzer
Turner Trilogy Fluorometer
Thermo Delta V gas chromatograph isotope ratio mass spectrometer (GC-IRMS)
U-3010 VIS Spectrophotometer
theme
None, User defined
Coulter Counter
Elemental Analyzer
Fluorometer
Gas Chromatograph
Spectrophotometer
instrument
BCO-DMO Standard Instruments
otherRestrictions
otherRestrictions
Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use.
CAREER: The biological nitrogen isotope systematics of ammonium consumption and production
https://osprey.bco-dmo.org/project/856532
CAREER: The biological nitrogen isotope systematics of ammonium consumption and production
<p><strong>NSF Award Abstract:</strong><br />
The nitrogen (N) cycle in the marine environment is controlled by biological processes. Unfortunately, quantifying these processes and assessing their effect on the N cycle is difficult by direct measurements because of large spatial and temporal differences. Isotopic composition measurements of N provide a means to constrain these processes indirectly; however, there is still a great deal to be understood about isotope fractionation of recycled nitrogen through biological processes, which has made interpretation of novel nitrogen isotope data difficult. A researcher from the University of Connecticut plans to determine the influence of biological consumption and production on the isotope fractionation in ammonium. By helping to understand the processes surrounding fractionation of recycled ammonium at the organism level, this research will create a basis for which future researchers can better interpret isotope composition data to infer nitrogen cycle dynamics. A graduate student, a postdoctoral fellow, and two or more undergraduate students will be involved in the research. The researcher plans to integrate science with community-engaged learning by developing an undergraduate field and laboratory course that will require the students to present their research to stakeholders in the community. There will be a manual created for this course that will be disseminated in open-access forums for teachers hoping to develop similar courses.</p>
<p>Biological nitrogen isotope fractionation associated with nitrogen recycling remains poorly constrained despite the advent of a variety of new techniques to analyze nitrogen isotopes in recent years. The use of isotopic composition data can be incredibly useful to interpreting nitrogen cycle processes in the ocean that are difficult to measure directly, which makes it crucial to further understand the processes behind fractionation to catch up with the advancement of the datasets available to researchers. This research will characterize the isotope fractionation dynamics of ammonium during biological consumption and production. The researchers will investigate whether the characteristic low concentrations of ammonium in the surface ocean affect isotope fractionation when the ammonium is recycled and whether there is a trophic isotope effect associated with ammonium recycling by protozoan grazers. With this research, there will be a baseline from which researchers can interpret recycled nitrogen dynamics from ammonium isotope datasets. The methods of comparing nitrogen cycling studies will become significantly clearer with such a standard making interpretation uniform by removing significant uncertainties.</p>
Biological Nitrogen Isotope Fractionation
largerWorkCitation
project
eng; USA
oceans
2024-03-08
0
BCO-DMO catalogue of parameters from Phytoplankton Nitrogen isotope fractionation from the Biological Nitrogen Isotope Fractionation project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
https://osprey.bco-dmo.org/dataset/921657/data/download
download
onLine
dataset
<p><strong>Phytoplankton cultures</strong></p>
<p>Two strains of marine algae, the diatom <em>Thalassiosira weissflogii</em> (actin) and the prasinophyte <em>Tetraselmis</em> sp. were grown in batch cultures in sterile, acid-washed borosilicate glass or polycarbonate bottles using artificial seawater medium in an environmental chamber at 18<sup>0</sup>C, illuminated with fluorescent light (40 <em>μ</em>mol photons m<sup>-2</sup> s<sup>-1</sup> photosynthetically available radiation) on a 12-hour light and 12-hour dark cycle. The artificial seawater medium was prepared from low nutrient Instant Ocean™ salt dissolved in Milli-Q water and filtered through a 47 mm Whatman GF/F glass microfiber filter (0.7 μm nominal pore-size) and sterilized by autoclaving at 100<sup>0</sup>C via Pasteurization cycle in PRIMUS steam sterilizer, then supplemented with filter-sterilized 100 – 250 <em>μ</em>M NH<sub>4</sub><sup>+</sup>, 10 <em>μ</em>M phosphate, 100 <em>μ</em>M silicic acid (only for <em>T. weissflogii</em> cultures), and f/2 trace metals and vitamins (Guillard and Ryther 1962). The batch cultures were initiated from inocula of approximately 1,000 cells mL<sup>-1</sup>, and cell densities monitored daily using Multisizer 4 Beckman Coulter counter. Media subsamples were collected during exponential growth for analyses of NH<sub>4</sub><sup>+</sup> concentration and N isotope ratios. Subsamples were filtered through a 0.45 μm pore-size polyether-sulfone (PES) syringe filters and collected into acid-washed High Density Poly-Ethylene (HDPE) bottles, solution pH adjusted to ca. 4.5 with dilute hydrochloric acid in order to minimize ammonia volatilization during storage, and samples stored at –20<sup>0</sup>C pending analysis. Particulate organic nitrogen (PON) was also sampled during the exponential growth phase by filtering aqueous subsamples onto a pre-combusted 25 mm Whatman GF/F glass microfiber filters (0.7 μm pore-size) and stored in pre-combusted aluminum foils at –20<sup>0</sup>C pending analysis of N isotope ratio analysis. To capture lower NH<sub>4</sub><sup>+</sup> concentrations, short-term NH<sub>4</sub><sup>+</sup> uptake experiments with <em>T. weissflogii</em> and <em>Tetraselmis</em> sp. were conducted. A first set of experiments was conducted with <em>T. weissflogii</em> and <em>Tetraselmis</em> sp. cells in early stationary phase, wherein NH<sub>4</sub><sup>+</sup> was exhausted from the medium. The cells were collected by gentle filtration onto a 5 μm pore-size 47 mm Isopore<sup>TM</sup> polycarbonate membrane filter and resuspended into fresh medium containing ~60 <em>μ</em>M NH<sub>4</sub><sup>+</sup> for <em>T. weissflogii</em> and 20 <em>μ</em>M NH<sub>4</sub><sup>+</sup> for <em>Tetraselmis</em> sp. Aqueous subsamples were collected at regular time intervals until NH<sub>4</sub><sup>+</sup> in the medium was exhausted. A second set of experiments was conducted with N-replete (cells in exponential growth phase) and N-starved cells (cells two days into stationary phase) of <em>T. weissflogii</em> and <em>Tetraselmis</em> sp. Cell cultures were either diluted into fresh medium containing ~20 µM NH<sub>4</sub><sup>+</sup>, or gently filtered onto a polycarbonate membrane filter and resuspended into said medium. Short-term incubations occurred largely under constant illumination, although some <em>Tetraselmis</em> sp. uptake experiments were inadvertently subject to light-dark conditions.</p>
<p><strong>Determination of NH<sub>4</sub><sup>+</sup> concentration</strong></p>
<p>Ammonium concentrations at or above 50 <em>μ</em>M were measured fluorometrically following derivatization with o-phthalaldehyde (OPA; Holmes et al. 1999) while concentrations &lt; 50 μM were analyzed with the indophenol method (Solórzano 1969).</p>
<p><strong>Analyses of N isotopes of NH<sub>4</sub><sup>+</sup> and PON</strong></p>
<p>Ammonium samples were diluted to 5 µM or 1 µM with deep Atlantic seawater and N isotope ratios determined using the hypobromite-azide method (Zhang et al. 2007), wherein NH<sub>4</sub><sup>+</sup> is first oxidized to nitrite by hypobromite, after which nitrite is converted to a nitrous oxide gas analyte by reacting with azide. The N isotopic composition of the nitrous oxide product was analyzed using a continuous flow purge and dual cryogenic trap system coupled to a custom-modified Gas Bench II device interfaced with a Thermo Delta V gas chromatograph isotope ratio mass spectrometer (GC-IRMS; see Casciotti et al. 2002; McIlvin and Casciotti 2011). Calibration to reference (dinitrogen gas in air) was achieved from parallel reactions of NH<sub>4</sub><sup>+</sup> reference materials IAEA-N1 and IAEA-N2 diluted in deep Atlantic seawater (5 µM or 1 µM solutions), with respective assigned δ<sup>15</sup>N values of 0.43‰ and 20.3‰ vs. air (Böhlke et al. 1993). To analyze N isotopes of PON, frozen glass microfiber filters were lyophilized for 24 hours using an Edwards Super Modulyo freeze-dryer. The filters were packed into tin capsules and analyzed by combustion to dinitrogen gas on a Costech ECS 4010 Elemental Analyzer followed by N isotope ratio analysis of the resulting dinitrogen gas on a Thermo Delta V isotope ratio mass spectrometer. Samples were calibrated with corresponding aliquots of L-glutamic acid reference materials USGS-40 and USGS-41, with δ<sup>15</sup>N values of –4.52 and 47.57‰ vs. air, respectively (Qi et al. 2003).</p>
Specified by the Principal Investigator(s)
<p>No data values are represented by blank cells in the data table. These values indicate that no sample was collected at the given time point.&nbsp;</p>
<p>Data were generated from the laboratory experiments were processed using Microsoft Excel.</p>
Specified by the Principal Investigator(s)
asNeeded
7.x-1.1
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
Multisizer 4 Beckman Coulter Counter
Multisizer 4 Beckman Coulter Counter
PI Supplied Instrument Name: Multisizer 4 Beckman Coulter Counter PI Supplied Instrument Description:A Multisizer 4 Beckman Coulter counter was used to determine phytoplankton cell density. Instrument Name: Coulter Counter Instrument Short Name: Instrument Description: An apparatus for counting and sizing particles suspended in electrolytes. It is used for cells, bacteria, prokaryotic cells and virus particles. A typical Coulter counter has one or more microchannels that separate two chambers containing electrolyte solutions.
from https://en.wikipedia.org/wiki/Coulter_counter
Costech ECS 4010 Elemental Analyzer
Costech ECS 4010 Elemental Analyzer
PI Supplied Instrument Name: Costech ECS 4010 Elemental Analyzer PI Supplied Instrument Description:A Costech ECS 4010 Elemental Analyzer coupled with a Thermo Delta V isotope ratio mass spectrometer was used for the combustion of PON samples to produce dinitrogen gas for N isotope analyses, with calibration achieved using L-glutamic acid references USGS-40 and USGS-41. Instrument Name: Elemental Analyzer Instrument Short Name: Instrument Description: Instruments that quantify carbon, nitrogen and sometimes other elements by combusting the sample at very high temperature and assaying the resulting gaseous oxides. Usually used for samples including organic material. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB01/
Turner Trilogy Fluorometer
Turner Trilogy Fluorometer
PI Supplied Instrument Name: Turner Trilogy Fluorometer PI Supplied Instrument Description:A Turner Trilogy Fluorometer was used to measure NH4+ concentration ≥ 50 µM. Instrument Name: Fluorometer Instrument Short Name:Fluorometer Instrument Description: A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. The instrument is designed to measure the amount of stimulated electromagnetic radiation produced by pulses of electromagnetic radiation emitted into a water sample or in situ. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/113/
Thermo Delta V gas chromatograph isotope ratio mass spectrometer (GC-IRMS)
Thermo Delta V gas chromatograph isotope ratio mass spectrometer (GC-IRMS)
PI Supplied Instrument Name: Thermo Delta V gas chromatograph isotope ratio mass spectrometer (GC-IRMS) PI Supplied Instrument Description:A Thermo Delta V gas chromatograph isotope ratio mass spectrometer (GC-IRMS) - used to analyze N isotopes of nitrous oxide gas derived from the chemical oxidation of NH4+ using the hypobromite-azide method (Zhang et al. 2007), with calibrations achieved using NH4+ reference materials IAEA-N1 and IAEA-N2. Instrument Name: Gas Chromatograph Instrument Short Name:Gas Chromatograph Instrument Description: Instrument separating gases, volatile substances, or substances dissolved in a volatile solvent by transporting an inert gas through a column packed with a sorbent to a detector for assay. (from SeaDataNet, BODC) Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB02/
U-3010 VIS Spectrophotometer
U-3010 VIS Spectrophotometer
PI Supplied Instrument Name: U-3010 VIS Spectrophotometer PI Supplied Instrument Description:A U-3010 VIS Spectrophotometer was used to measure NH4+ concentration < 50 µM. Instrument Name: Spectrophotometer Instrument Short Name:Spectrophotometer Instrument Description: An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB20/