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Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean

We measured pools of dissolved phosphorus (P), including dissolved inorganic P (DIP), dissolved organic P (DOP) and alkaline phosphatase (AP)-hydrolyzable labile DOP (L-DOP), and kinetic parameters of AP activity (APA) in the euphotic zone in the western North Pacific Ocean. Samples were collected f...

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Autores principales: Suzumura, Masahiro, Hashihama, Fuminori, Yamada, Namiha, Kinouchi, Shinko
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Research Foundation 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3307022/
https://www.ncbi.nlm.nih.gov/pubmed/22457661
http://dx.doi.org/10.3389/fmicb.2012.00099
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author Suzumura, Masahiro
Hashihama, Fuminori
Yamada, Namiha
Kinouchi, Shinko
author_facet Suzumura, Masahiro
Hashihama, Fuminori
Yamada, Namiha
Kinouchi, Shinko
author_sort Suzumura, Masahiro
collection PubMed
description We measured pools of dissolved phosphorus (P), including dissolved inorganic P (DIP), dissolved organic P (DOP) and alkaline phosphatase (AP)-hydrolyzable labile DOP (L-DOP), and kinetic parameters of AP activity (APA) in the euphotic zone in the western North Pacific Ocean. Samples were collected from one coastal station in Sagami Bay, Japan, and three offshore stations between the North Pacific subtropical gyre (NPSG) and the Kuroshio region. Although DIP concentrations in the euphotic zone at all stations were equally low, around the nominal method detection limit of 20 nmol L(-1), chlorophyll a (Chl a) concentrations were one order of magnitude greater at the coastal station. DOP was the dominant P pool, comprising 62–92% of total dissolved P at and above the Chl a maximum layer (CML). L-DOP represented 22–39% of the total DOP at the offshore stations, whereas it accounted for a much higher proportion (about 85%) in the coastal surface layers. Significant correlations between maximum potential AP hydrolysis rates and DIP concentrations or bacterial cell abundance in the offshore euphotic zone suggest that major APA in the oligotrophic surface ocean is from bacterial activity and regulated largely by DIP availability. Although the range of maximum potential APA was comparable among the environmental conditions, the in situ hydrolysis rate of L-DOP in the coastal station was 10 times those in the offshore stations. L-DOP turnover time at the CML ranged from 4.5 days at the coastal station to 84.4 days in the NPSG. The ratio of the APA half-saturation constant to the ambient L-DOP concentration decreased markedly from the NPSG to the coastal station. There were substantial differences in the rate and efficiency of DOP remineralization and its contribution as the potential P source between the low-phosphate/high-biomass coastal ecosystem and the low-phosphate/low biomass oligotrophic ocean.
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spelling pubmed-33070222012-03-28 Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean Suzumura, Masahiro Hashihama, Fuminori Yamada, Namiha Kinouchi, Shinko Front Microbiol Microbiology We measured pools of dissolved phosphorus (P), including dissolved inorganic P (DIP), dissolved organic P (DOP) and alkaline phosphatase (AP)-hydrolyzable labile DOP (L-DOP), and kinetic parameters of AP activity (APA) in the euphotic zone in the western North Pacific Ocean. Samples were collected from one coastal station in Sagami Bay, Japan, and three offshore stations between the North Pacific subtropical gyre (NPSG) and the Kuroshio region. Although DIP concentrations in the euphotic zone at all stations were equally low, around the nominal method detection limit of 20 nmol L(-1), chlorophyll a (Chl a) concentrations were one order of magnitude greater at the coastal station. DOP was the dominant P pool, comprising 62–92% of total dissolved P at and above the Chl a maximum layer (CML). L-DOP represented 22–39% of the total DOP at the offshore stations, whereas it accounted for a much higher proportion (about 85%) in the coastal surface layers. Significant correlations between maximum potential AP hydrolysis rates and DIP concentrations or bacterial cell abundance in the offshore euphotic zone suggest that major APA in the oligotrophic surface ocean is from bacterial activity and regulated largely by DIP availability. Although the range of maximum potential APA was comparable among the environmental conditions, the in situ hydrolysis rate of L-DOP in the coastal station was 10 times those in the offshore stations. L-DOP turnover time at the CML ranged from 4.5 days at the coastal station to 84.4 days in the NPSG. The ratio of the APA half-saturation constant to the ambient L-DOP concentration decreased markedly from the NPSG to the coastal station. There were substantial differences in the rate and efficiency of DOP remineralization and its contribution as the potential P source between the low-phosphate/high-biomass coastal ecosystem and the low-phosphate/low biomass oligotrophic ocean. Frontiers Research Foundation 2012-03-19 /pmc/articles/PMC3307022/ /pubmed/22457661 http://dx.doi.org/10.3389/fmicb.2012.00099 Text en Copyright © 2012 Suzumura, Hashihama, Yamada and Kinouchi. http://www.frontiersin.org/licenseagreement This is an open-access article distributed under the terms of the Creative Commons Attribution Non Commercial License, which permits non-commercial use, distribution, and reproduction in other forums, provided the original authors and source are credited.
spellingShingle Microbiology
Suzumura, Masahiro
Hashihama, Fuminori
Yamada, Namiha
Kinouchi, Shinko
Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean
title Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean
title_full Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean
title_fullStr Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean
title_full_unstemmed Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean
title_short Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean
title_sort dissolved phosphorus pools and alkaline phosphatase activity in the euphotic zone of the western north pacific ocean
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3307022/
https://www.ncbi.nlm.nih.gov/pubmed/22457661
http://dx.doi.org/10.3389/fmicb.2012.00099
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