Extracellular enzyme activity in the coastal upwelling system off Peru: a mesocosm experiment
<p>The Peruvian upwelling system is a highly productive ecosystem with a large oxygen minimum zone (OMZ) close to the surface. In this work, we carried out a mesocosm experiment off Callao, Peru, with the addition of water masses from the regional OMZ collected at two different sites simulatin...
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-04-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/20/1605/2023/bg-20-1605-2023.pdf |
| _version_ | 1827962968831164416 |
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| author | K. Spilling K. Spilling J. Piiparinen E. P. Achterberg J. Arístegui L. T. Bach M. T. Camarena-Gómez E. von der Esch M. A. Fischer M. Gómez-Letona N. Hernández-Hernández J. Meyer R. A. Schmitz U. Riebesell |
| author_facet | K. Spilling K. Spilling J. Piiparinen E. P. Achterberg J. Arístegui L. T. Bach M. T. Camarena-Gómez E. von der Esch M. A. Fischer M. Gómez-Letona N. Hernández-Hernández J. Meyer R. A. Schmitz U. Riebesell |
| author_sort | K. Spilling |
| collection | DOAJ |
| description | <p>The Peruvian upwelling system is a highly productive ecosystem with a large
oxygen minimum zone (OMZ) close to the surface. In this work, we carried out a
mesocosm experiment off Callao, Peru, with the addition of water masses from
the regional OMZ collected at two different sites simulating two different
upwelling scenarios. Here, we focus on the pelagic remineralization of organic
matter by the extracellular enzyme activity of leucine aminopeptidase (LAP) and
alkaline phosphatase activity (APA). After the addition of the OMZ water,
dissolved inorganic nitrogen (N) was depleted, but the standing stock of
phytoplankton was relatively high, even after N depletion (mostly
<span class="inline-formula"><i>></i></span> 4 <span class="inline-formula">µ</span>g chlorophyll <span class="inline-formula"><i>a</i></span> L<span class="inline-formula"><sup>−1</sup></span>). During the initial phase of
the experiment, APA was 0.6 nmol L<span class="inline-formula"><sup>−1</sup></span> h<span class="inline-formula"><sup>−1</sup></span> even though the
PO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">3</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="be4361b88ba45665094821599c6616ef"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-1605-2023-ie00001.svg" width="13pt" height="17pt" src="bg-20-1605-2023-ie00001.png"/></svg:svg></span></span> concentration was <span class="inline-formula"><i>></i></span> 0.5 <span class="inline-formula">µ</span>mol L<span class="inline-formula"><sup>−1</sup></span>.
Initially, the dissolved organic phosphorus (DOP) decreased, coinciding with
an increase in the PO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">3</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="1942e7716e2a9166d2a38b0e436e30e1"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-1605-2023-ie00002.svg" width="13pt" height="17pt" src="bg-20-1605-2023-ie00002.png"/></svg:svg></span></span> concentration that was probably linked to the APA. The
LAP activity was very high, with most of the measurements in the range of
200–800 nmol L<span class="inline-formula"><sup>−1</sup></span> h<span class="inline-formula"><sup>−1</sup></span>. This enzyme hydrolyzes terminal amino acids
from larger molecules (e.g., peptides or proteins), and these high values are
probably linked to the highly productive but N-limited coastal ecosystem.
Moreover, the experiment took place during a rare coastal El Niño event with
higher than normal surface temperatures, which could have affected enzyme
activity. Using a nonparametric multidimensional scaling analysis (NMDS)
with a generalized additive model (GAM), we found that biogeochemical
variables (e.g., nutrient and chlorophyll-<span class="inline-formula"><i>a</i></span> concentrations) and phytoplankton and
bacterial communities explained up to 64 % of the variability in APA. The
bacterial community best explained the variability (34 %) in LAP. The high
hydrolysis rates for this enzyme suggest that pelagic N remineralization,
likely driven by the bacterial community, supported the high standing stock
of primary producers in the mesocosms after N depletion.</p> |
| first_indexed | 2024-04-09T16:50:52Z |
| format | Article |
| id | doaj.art-103beb01dc1547e7a8d8abd20167e80e |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-04-09T16:50:52Z |
| publishDate | 2023-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-103beb01dc1547e7a8d8abd20167e80e2023-04-21T12:13:15ZengCopernicus PublicationsBiogeosciences1726-41701726-41892023-04-01201605161910.5194/bg-20-1605-2023Extracellular enzyme activity in the coastal upwelling system off Peru: a mesocosm experimentK. Spilling0K. Spilling1J. Piiparinen2E. P. Achterberg3J. Arístegui4L. T. Bach5M. T. Camarena-Gómez6E. von der Esch7M. A. Fischer8M. Gómez-Letona9N. Hernández-Hernández10J. Meyer11R. A. Schmitz12U. Riebesell13Marine and Freshwater Solutions, Finnish Environment Institute, Helsinki, FinlandCentre for Coastal Research, University of Agder, Kristiansand, NorwayMarine and Freshwater Solutions, Finnish Environment Institute, Helsinki, FinlandGEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, GermanyInstituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, SpainInstitute for Marine and Antarctic Studies, University of Tasmania, Tasmania, AustraliaCentro Oceanográfico de Málaga, Instituto Español De Oceanografía, IEO-CSIC, Málaga, SpainInstitute of Hydrochemistry, Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, Munich, GermanyInstitute for General Microbiology, Christian-Albrechts University of Kiel, Kiel, GermanyInstituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, SpainInstituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, SpainGEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, GermanyInstitute for General Microbiology, Christian-Albrechts University of Kiel, Kiel, GermanyGEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany<p>The Peruvian upwelling system is a highly productive ecosystem with a large oxygen minimum zone (OMZ) close to the surface. In this work, we carried out a mesocosm experiment off Callao, Peru, with the addition of water masses from the regional OMZ collected at two different sites simulating two different upwelling scenarios. Here, we focus on the pelagic remineralization of organic matter by the extracellular enzyme activity of leucine aminopeptidase (LAP) and alkaline phosphatase activity (APA). After the addition of the OMZ water, dissolved inorganic nitrogen (N) was depleted, but the standing stock of phytoplankton was relatively high, even after N depletion (mostly <span class="inline-formula"><i>></i></span> 4 <span class="inline-formula">µ</span>g chlorophyll <span class="inline-formula"><i>a</i></span> L<span class="inline-formula"><sup>−1</sup></span>). During the initial phase of the experiment, APA was 0.6 nmol L<span class="inline-formula"><sup>−1</sup></span> h<span class="inline-formula"><sup>−1</sup></span> even though the PO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">3</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="be4361b88ba45665094821599c6616ef"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-1605-2023-ie00001.svg" width="13pt" height="17pt" src="bg-20-1605-2023-ie00001.png"/></svg:svg></span></span> concentration was <span class="inline-formula"><i>></i></span> 0.5 <span class="inline-formula">µ</span>mol L<span class="inline-formula"><sup>−1</sup></span>. Initially, the dissolved organic phosphorus (DOP) decreased, coinciding with an increase in the PO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mrow><mn mathvariant="normal">3</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="1942e7716e2a9166d2a38b0e436e30e1"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-1605-2023-ie00002.svg" width="13pt" height="17pt" src="bg-20-1605-2023-ie00002.png"/></svg:svg></span></span> concentration that was probably linked to the APA. The LAP activity was very high, with most of the measurements in the range of 200–800 nmol L<span class="inline-formula"><sup>−1</sup></span> h<span class="inline-formula"><sup>−1</sup></span>. This enzyme hydrolyzes terminal amino acids from larger molecules (e.g., peptides or proteins), and these high values are probably linked to the highly productive but N-limited coastal ecosystem. Moreover, the experiment took place during a rare coastal El Niño event with higher than normal surface temperatures, which could have affected enzyme activity. Using a nonparametric multidimensional scaling analysis (NMDS) with a generalized additive model (GAM), we found that biogeochemical variables (e.g., nutrient and chlorophyll-<span class="inline-formula"><i>a</i></span> concentrations) and phytoplankton and bacterial communities explained up to 64 % of the variability in APA. The bacterial community best explained the variability (34 %) in LAP. The high hydrolysis rates for this enzyme suggest that pelagic N remineralization, likely driven by the bacterial community, supported the high standing stock of primary producers in the mesocosms after N depletion.</p>https://bg.copernicus.org/articles/20/1605/2023/bg-20-1605-2023.pdf |
| spellingShingle | K. Spilling K. Spilling J. Piiparinen E. P. Achterberg J. Arístegui L. T. Bach M. T. Camarena-Gómez E. von der Esch M. A. Fischer M. Gómez-Letona N. Hernández-Hernández J. Meyer R. A. Schmitz U. Riebesell Extracellular enzyme activity in the coastal upwelling system off Peru: a mesocosm experiment Biogeosciences |
| title | Extracellular enzyme activity in the coastal upwelling system off Peru: a mesocosm experiment |
| title_full | Extracellular enzyme activity in the coastal upwelling system off Peru: a mesocosm experiment |
| title_fullStr | Extracellular enzyme activity in the coastal upwelling system off Peru: a mesocosm experiment |
| title_full_unstemmed | Extracellular enzyme activity in the coastal upwelling system off Peru: a mesocosm experiment |
| title_short | Extracellular enzyme activity in the coastal upwelling system off Peru: a mesocosm experiment |
| title_sort | extracellular enzyme activity in the coastal upwelling system off peru a mesocosm experiment |
| url | https://bg.copernicus.org/articles/20/1605/2023/bg-20-1605-2023.pdf |
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