Phosphorus acquisition by Chlamydomonas acidophila under autotrophic and osmo-mixotrophic growth conditions
Chlamydomonas acidophila Negoro is a green algal species abundant in acidic waters where inorganic phosphorus (P(i)) and carbon (CO(2)) are considered the most important growth-limiting nutrients for the phytoplankton. This paper describes the P(i) uptake and growth kinetics under varying carbon sup...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 58(2007), 15-16 vom: 25., Seite 4195-202 |
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| 1. Verfasser: | |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2007
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Carbon Dioxide 142M471B3J Phosphorus 27YLU75U4W Phosphoric Monoester Hydrolases EC 3.1.3.2 Glucose IY9XDZ35W2 |
| Zusammenfassung: | Chlamydomonas acidophila Negoro is a green algal species abundant in acidic waters where inorganic phosphorus (P(i)) and carbon (CO(2)) are considered the most important growth-limiting nutrients for the phytoplankton. This paper describes the P(i) uptake and growth kinetics under varying carbon supply by cultivating the alga autotrophically, with and without CO(2) aeration, and osmo-mixotrophically with glucose under low P(i) conditions at pH 2.7. The low minimum cellular phosphorus quota (Q(0); ranging from 0.6 to 1.1 mmol P mol(-1) C) suggested P(i)-limiting conditions under all different modes of carbon supply, and was lowest under CO(2)-aerated conditions. The threshold P(i) concentration for growth did not vary from zero, suggesting no detectable metabolic costs. Maximum P(i)-uptake rates (V(max)) were a better indication of P(i) limitation when compared with the affinity constant for P(i) uptake (K(m)), as V(max) was only high under P(i)-limited conditions whereas K(m) was low under both P(i)-limited and P(i)-replete conditions. Osmo-mixotrophic growth conditions did not result in decreased extracellular phosphatase activity, but often resulted in physiological characteristics comparable with CO(2)-aerated cells, suggesting intracellular CO(2) production by glucose respiration. In addition, at low CO(2) and in autotrophic conditions, C. acidophila had a higher Q(0), lower dissolved organic carbon concentration, lower maximum P(i)-uptake rates, and lower phosphatase activity, suggesting that growth was co-limited by CO(2) and P(i). Furthermore, cells may respond physiologically to both nutrient limitations simultaneously |
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| Beschreibung: | Date Completed 28.04.2008 Date Revised 24.11.2016 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |