Comparison of phosphate uptake rates by the smallest plastidic and aplastidic protists in the North Atlantic subtropical gyre
The smallest phototrophic protists (< 3 mu m) are important primary producers in oligotrophic subtropical gyres - the Earth's largest ecosystems. In order to elucidate how these protists meet their inorganic nutrient requirements, we compared the phosphate uptake rates of plastidic and aplas...
| Published in: | FEMS Microbiology Ecology |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
Wiley-Blackwell Publishing Ltd.
2011
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| Subjects: | |
| Online Access: | http://wrap.warwick.ac.uk/40324/ https://doi.org/10.1111/j.1574-6941.2011.01160.x |
| Summary: | The smallest phototrophic protists (< 3 mu m) are important primary producers in oligotrophic subtropical gyres - the Earth's largest ecosystems. In order to elucidate how these protists meet their inorganic nutrient requirements, we compared the phosphate uptake rates of plastidic and aplastidic protists in the phosphate-depleted subtropical and tropical North Atlantic (4-29 degrees N) using a combination of radiotracers and flow cytometric sorting on two Atlantic Meridional Transect cruises. Plastidic protists were divided into two groups according to their size (< 2 and 2-3 mu m). Both groups of plastidic protists showed higher phosphate uptake rates per cell than the aplastidic protists. Although the phosphate uptake rates of protist cells were on average seven times (P < 0.001) higher than those of bacterioplankton, the biomass-specific phosphate uptake rates of protists were one fourth to one twentieth of an average bacterioplankton cell. The unsustainably low biomass-specific phosphate uptake by both plastidic and aplastidic protists suggests the existence of a common alternative means of phosphorus acquisition - predation on phosphorus-rich bacterioplankton cells. |
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