Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Horrigan, S.G.
Right arrow Articles by McCarthy, J.J.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Horrigan, S.G.
Right arrow Articles by McCarthy, J.J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

JOURNAL OF PLANKTON RESEARCH | VOLUME 3 | NUMBER 3 | PAGES 403-414 | 1981
© Oxford University Press

research-article

Urea uptake by phytoplankton at various stages of nutrient depletion

S.G. Horrigan and J.J. McCarthy*

Institute of Marine Resources, A-018, Scripps Institution of Oceanography, Univeristy of California San Diego, La Jolla, California 92093 *Museum of Comparative Zoology, Harvard University Cambridge, Mass. 02138

Received on August 1, 1980; accepted on February 1, 1981 Uptake of 14C-urea by Thalassiosira pseudonana and Skeletonema costatum grown in batch culture with NO2– and NO3– as nitrogen sources was measured under three conditions: pre-depletion (when nitrogenous nutrient was present in the culture medium at saturating concentrations), at-depletion (when nitrogenous nutrient could no longer be detected), and several hours post-depletion. Vmax-urea, the initial instantaneous uptake rate, remained constant under all three conditions, and was in excess of uptake rates required for cellular doubling. Variations in uptake under the three conditions were observed, as functions of the length of time over which uptake was observed and the growth rate of the culture. The maximum instantaneous uptake rate was not different for the three conditions; variations in uptake were due to the period of time over which the maximum uptake rate was maintained. The ability of cells to take up urea rapidly, even when adequately nourished by NO2– and NO3–, could be of significance in a low and variable urea-nutrient regime in the natural environment.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.