5 Result(s)
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Article
Comparison between chemical and isotopic measurements of biological nitrate utilization: further evidence of low new-production levels in the equatorial Pacific
New-production (nitrate uptake) rates in the equatorial Pacific were estimated by parallel measurements of nitrate disappearance from sea water using a colorimetric method and of 15N-labelled nitrate (15NO3 ...
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Article
Feasibility of using an automated colorimetric procedure for the determination of seawater nitrate in the 0 to 100 nM range: Examples from field and culture
An automatic colorimetric procedure for measuring nanomolar quantities of nitrate and nitrite in seawater has been improved in sensitivity. Application of this method toin situ investigations in the North Atlanti...
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Article
Biosynthetically active glutamine synthetase in the marine diatom Phaeodactylum tricornutum: optimization of the forward-reaction assay
The activity of glutamine synthetase (GS) was measured in the marine diatom Phaeodactylum tricornutum Bohlin (Strain SME) by a biosynthetic assay, based on γ-glutamyl hydroxamate synthesis, and referred to as the...
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Article
Significance of cellular nitrate content in natural populations of marine phytoplankton growing in shipboard cultures
Phytoplankton intracellular nitrate concentrations have been monitored in a 56-h experiment on a shipboard culture of surface sea water from an upwelling region. These measurements were related to parameters o...
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Article
An automated assay for the determination of nitrate reductase in marine phytoplankton
Nitrate reductase activity in marine phytoplankton has been assayed on a Technicon AutoAnalyzer®. A description of the automation is given with details of the apparatus and procedure. Twenty samples an hour can b...
