Carbon limitation of ammonium uptake by heterotrophic bacteria in the subarctic Pacific
The purpose of this study was to test the hypothesis that NH4+ uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 μM) stimulated NH4+ uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH4+ uptake was even...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Article in Journal/Newspaper |
| Language: | English unknown |
| Published: |
American Society of Limnology and Oceanography, Inc.
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| Subjects: | |
| Online Access: | https://ir.library.oregonstate.edu/concern/articles/08612q175 |
| Summary: | The purpose of this study was to test the hypothesis that NH4+ uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 μM) stimulated NH4+ uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH4+ uptake was even greater in the bacterial size fraction (<0.8 μm). Regeneration of 15NH4+ from added [15N] amino acids was measurable in the bacterial size fraction, but glucose additions prevented net NH4+ excretion because of increased uptake of NH4+. In the subarctic Pacific, NH4+ concentrations range from undetectable (≤0.05 μM) to 0.4 μM, whereas the maximal estimate of monosaccharide concentrations was 0.025 μM. These results indicate that the supply of C compounds like glucose can limit NH4+ uptake by heterotrophic bacteria. |
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