Carbon limitation of ammonium uptake by heterotrophic bacteria in the subarctic Pacific
The purpose of this study was to test the hypothesis that NH 4 + uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 µ M) stimulted NH 4 + uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH 4 + uptake wa...
Published in: | Limnology and Oceanography |
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Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
1990
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Subjects: | |
Online Access: | http://dx.doi.org/10.4319/lo.1990.35.6.1258 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1990.35.6.1258 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1990.35.6.1258 |
Summary: | The purpose of this study was to test the hypothesis that NH 4 + uptake by heterotrophic bacteria in the subarctic Pacific is C limited. Addition of glucose (0.5–1.0 µ M) stimulted NH 4 + uptake in unfractionated water but had no effect on bacterial abundance. Glucose stimulation of NH 4 + uptake was even greater in the bacterial size fraction (<0.8 µ m). Regeneration of 15 NH 4 + from added [ 15 N] amino acids was measurable in the bacterial size fraction, but glucose additions prevented net NH 4 + excretion because of increased uptake of NH 4 + . In the subarctic Pacific, NH 4 + concentrations range from undetectable (≤0.05 µ M) to 0.4 µ M, whereas the maximal estimate of monosaccharide concentrations was 0.025 M. These results indicate that the supply of C compounds like glucose can limit NH 4 + uptake by heterotrophic bacteria. |
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