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Science 15 March 1985:
Vol. 227. no. 4692, pp. 1338 - 1340
DOI: 10.1126/science.227.4692.1338
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Articles

Bacterial 5-Nucleotidase in Aquatic Ecosystems: A Novel Mechanism of Phosphorus Regeneration

JAMES W. AMMERMAN 1 and FAROOQ AZAM 1

1 Institute of Marine Resources, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093

Zooplankton excretion and algal alkaline phosphatase are presumed to be responsible for phosphorus recycling in aquatic ecosystems; the role of bacteria has been unclear. High levels of bacterial cell-surface 5-nucleotidase were discovered in samples of picoplankton from California coastal waters. 5-Nucleotidase rapidly generated orthophosphate from 5-nucleotide added in nanomolar amounts and could supply half the orthophosphate required by plankton. Unlike alkaline phosphatase, 5-nucleotidase was not inhibited by orthophosphate at any concentration found in aquatic environments. Initial results indicate even greater 5-nucleotidase activity in fresh water (Lake Hodges, California) and brackish water (Baltic). Release and uptake of orthophosphate were tightly coupled.

Submitted on July 27, 1984
Accepted on November 23, 1984


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Seasonal Variations in the Contributions of Different Bacterial Groups to the Uptake of Low-Molecular-Weight Compounds in Northwestern Mediterranean Coastal Waters.
L. Alonso-Saez and J. M. Gasol (2007)
Appl. Envir. Microbiol. 73, 3528-3535
   Abstract »    Full Text »    PDF »
Characterization of ectoenzyme activity and phosphate-regulated proteins in the coccolithophorid Emiliania huxleyi.
S. T. Dyhrman and B. Palenik (2003)
J. Plankton Res. 25, 1215-1225
   Abstract »    Full Text »    PDF »


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