Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production
ABSTRACT Given the potential significance of enzyme activities as a link between internal metabolic pathways and environmental nutrients, we investigated the relationships of nitrate reductase (NR) and alkaline phosphatase (AP) with primary production and inorganic nutrients in South Shetland Island...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.1039.6891 2023-05-15T13:45:20+02:00 Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production José L Iriarte Rodrigo R González Renato A Quiñones Sung-Ho Kang Jae H Shim Cynthia P Valenzuela The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1039.6891 http://rchn.biologiachile.cl/pdfs/2006/4/Iriarte_et_al_2006.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1039.6891 http://rchn.biologiachile.cl/pdfs/2006/4/Iriarte_et_al_2006.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://rchn.biologiachile.cl/pdfs/2006/4/Iriarte_et_al_2006.pdf text ftciteseerx 2020-03-08T01:21:06Z ABSTRACT Given the potential significance of enzyme activities as a link between internal metabolic pathways and environmental nutrients, we investigated the relationships of nitrate reductase (NR) and alkaline phosphatase (AP) with primary production and inorganic nutrients in South Shetland Islands, Antarctica. Enzymatic activities of the phytoplankton (0.7-210 μm), primary productivity, autotrophic biomass and inorganic nutrients were studied in the upper 100 m depth at nine stations during a cruise in the northwestern area of South Shetland Islands (Antarctica), during late austral spring (December 2000). NR activities fluctuated between 0 and 42.8 nmol L -1 h -1 (mean = 10.08 nmol L -1 h -1 , SD = 10.42 nmol L -1 h -1 ), AP activities between 0.81 and 5.67 nmol L -1 h -1 (mean = 2.68 nmol L -1 h -1 , SD = 0.95 nmol L -1 h -1 ). Stations with primary productivity (PP) and chlorophyll a greater than 2 mg C m -3 h -1 and 0.75 μg chlorophyll a L -1 , respectively, presented higher enzymatic activities of nitrate reductase, alkaline phosphatase than those stations characterized by primary productivity and chlorophyll a less than 2 mg C m -3 h -1 and 0.17 μg chlorophyll a L -1 , respectively. The AP specific activity was negatively correlated with orthophosphate concentrations lower than 2.0 μM, which indicates that the microplankton were under phosphate deficient environment condition. Our results indicated that NR specific activity was positively associated with autotrophic biomass and primary productivity estimates, giving evidence of the use of nitrate by phytoplankton as external nitrogen source in surface waters. In addition, high NR activities were positively correlated with NO 3 -, suggesting the occurrence of nitrate respiration in the well oxygenated surface waters of Antarctica. Key words: nitrate reductase, alkaline phosphatase, primary productivity, chlorophyll, Antarctica. RESUMEN Dada la potencial importancia de la actividad enzimática de ensambles fitoplanctónicos, como indicador de su metabolismo ... Text Antarc* Antarctica South Shetland Islands Unknown Austral South Shetland Islands |
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Open Polar |
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Unknown |
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English |
description |
ABSTRACT Given the potential significance of enzyme activities as a link between internal metabolic pathways and environmental nutrients, we investigated the relationships of nitrate reductase (NR) and alkaline phosphatase (AP) with primary production and inorganic nutrients in South Shetland Islands, Antarctica. Enzymatic activities of the phytoplankton (0.7-210 μm), primary productivity, autotrophic biomass and inorganic nutrients were studied in the upper 100 m depth at nine stations during a cruise in the northwestern area of South Shetland Islands (Antarctica), during late austral spring (December 2000). NR activities fluctuated between 0 and 42.8 nmol L -1 h -1 (mean = 10.08 nmol L -1 h -1 , SD = 10.42 nmol L -1 h -1 ), AP activities between 0.81 and 5.67 nmol L -1 h -1 (mean = 2.68 nmol L -1 h -1 , SD = 0.95 nmol L -1 h -1 ). Stations with primary productivity (PP) and chlorophyll a greater than 2 mg C m -3 h -1 and 0.75 μg chlorophyll a L -1 , respectively, presented higher enzymatic activities of nitrate reductase, alkaline phosphatase than those stations characterized by primary productivity and chlorophyll a less than 2 mg C m -3 h -1 and 0.17 μg chlorophyll a L -1 , respectively. The AP specific activity was negatively correlated with orthophosphate concentrations lower than 2.0 μM, which indicates that the microplankton were under phosphate deficient environment condition. Our results indicated that NR specific activity was positively associated with autotrophic biomass and primary productivity estimates, giving evidence of the use of nitrate by phytoplankton as external nitrogen source in surface waters. In addition, high NR activities were positively correlated with NO 3 -, suggesting the occurrence of nitrate respiration in the well oxygenated surface waters of Antarctica. Key words: nitrate reductase, alkaline phosphatase, primary productivity, chlorophyll, Antarctica. RESUMEN Dada la potencial importancia de la actividad enzimática de ensambles fitoplanctónicos, como indicador de su metabolismo ... |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
José L Iriarte Rodrigo R González Renato A Quiñones Sung-Ho Kang Jae H Shim Cynthia P Valenzuela |
spellingShingle |
José L Iriarte Rodrigo R González Renato A Quiñones Sung-Ho Kang Jae H Shim Cynthia P Valenzuela Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production |
author_facet |
José L Iriarte Rodrigo R González Renato A Quiñones Sung-Ho Kang Jae H Shim Cynthia P Valenzuela |
author_sort |
José L Iriarte |
title |
Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production |
title_short |
Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production |
title_full |
Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production |
title_fullStr |
Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production |
title_full_unstemmed |
Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production |
title_sort |
enzyme activities of phytoplankton in the south shetland islands (antarctica) in relation to nutrients and primary production |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1039.6891 http://rchn.biologiachile.cl/pdfs/2006/4/Iriarte_et_al_2006.pdf |
geographic |
Austral South Shetland Islands |
geographic_facet |
Austral South Shetland Islands |
genre |
Antarc* Antarctica South Shetland Islands |
genre_facet |
Antarc* Antarctica South Shetland Islands |
op_source |
http://rchn.biologiachile.cl/pdfs/2006/4/Iriarte_et_al_2006.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1039.6891 http://rchn.biologiachile.cl/pdfs/2006/4/Iriarte_et_al_2006.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766220860980461568 |