Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production

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, Antarc...

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Autores principales: IRIARTE,JOSÉ L, GONZÁLEZ,RODRIGO R, QUIÑONES,RENATO A, KANG,SUNG-HO, SHIM,JAE H, VALENZUELA,CYNTHIA P
Lenguaje:English
Publicado: Sociedad de Biología de Chile 2006
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Acceso en línea:http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2006000400009
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spelling oai:scielo:S0716-078X20060004000092014-01-23Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary productionIRIARTE,JOSÉ LGONZÁLEZ,RODRIGO RQUIÑONES,RENATO AKANG,SUNG-HOSHIM,JAE HVALENZUELA,CYNTHIA P nitrate reductase alkaline phosphatase primary productivity chlorophyll Antarctica 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 mg 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 mg 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 NO3-, suggesting the occurrence of nitrate respiration in the well oxygenated surface waters of Antarcticainfo:eu-repo/semantics/openAccessSociedad de Biología de ChileRevista chilena de historia natural v.79 n.4 20062006-12-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2006000400009en10.4067/S0716-078X2006000400009
institution Scielo Chile
collection Scielo Chile
language English
topic nitrate reductase
alkaline phosphatase
primary productivity
chlorophyll
Antarctica
spellingShingle nitrate reductase
alkaline phosphatase
primary productivity
chlorophyll
Antarctica
IRIARTE,JOSÉ L
GONZÁLEZ,RODRIGO R
QUIÑONES,RENATO A
KANG,SUNG-HO
SHIM,JAE H
VALENZUELA,CYNTHIA P
Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica) in relation to nutrients and primary production
description 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 mg 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 mg 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 NO3-, suggesting the occurrence of nitrate respiration in the well oxygenated surface waters of Antarctica
author IRIARTE,JOSÉ L
GONZÁLEZ,RODRIGO R
QUIÑONES,RENATO A
KANG,SUNG-HO
SHIM,JAE H
VALENZUELA,CYNTHIA P
author_facet IRIARTE,JOSÉ L
GONZÁLEZ,RODRIGO R
QUIÑONES,RENATO A
KANG,SUNG-HO
SHIM,JAE H
VALENZUELA,CYNTHIA P
author_sort IRIARTE,JOSÉ L
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
publisher Sociedad de Biología de Chile
publishDate 2006
url http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2006000400009
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