Effect of nitrogen source and growth rate on phytoplankton‐mediated changes in alkalinity1
Continuous cultures of the marine chrysophyte Dunaliella tertiolecta were grown on four nitrogen sources: NO 3 NO 2 − , NH 4 +, and urea. Alkalinity changes were consistent with a simple stoichiometric model in which OH production is balanced by NO 3 − and NO 2 − uptake, H + production is balanced b...
| Published in: | Limnology and Oceanography |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
1980
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.4319/lo.1980.25.2.0352 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1980.25.2.0352 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1980.25.2.0352 |
| Summary: | Continuous cultures of the marine chrysophyte Dunaliella tertiolecta were grown on four nitrogen sources: NO 3 NO 2 − , NH 4 +, and urea. Alkalinity changes were consistent with a simple stoichiometric model in which OH production is balanced by NO 3 − and NO 2 − uptake, H + production is balanced by NH 4 + uptake and no change occurs when the uncharged species urea is assimilated. Neither the influent N concentration nor the growth rate had any effect on the 1:1 stoichiometry between N uptake and alkalinity change. These results preclude the possibility of excretion of an organic acid (e.g. glycolic acid) stronger than carbonic acid. However, excretion of a weak organic acid or a salt of a strong organic acid cannot be ruled out. In general, the results are consistent with the notion that excretion of glycolic acid by healthy marine phytoplankton cells is minimal. |
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