Effects of light on nitrate-limited Oscillatoria agardhii in chemostat cultures |
| |
Authors: | Wanda Zevenboom Gerard J. de Groot Luuc R. Mur |
| |
Affiliation: | (1) Laboratorium voor Microbiologie, Universiteit van Amsterdam, Nieuwe Achtergracht 127, NL-1018 WS Amsterdam, The Netherlands |
| |
Abstract: | The effects of the average light irradiance ( I ) on growth and nitrate uptake kinetics of the cyanobacterium Oscillatoria agardhii, in nitrate-limited chemostat cultures, were studied. Light was nonsaturating for I <9.4 Wm–2, for all growth rates ( ) studied. However, was throughout limited by the availability of nitrate. Under light-saturating conditions the kinetics of nitrate-limited growth could be adequately described by both the Monod and Droop equations. Under light-non-saturating conditions the internal nitrogen content (Q) was a function of both and I , for which new formulas were derived. The high uptake capacity (Vmax) of nitrate-limited cells was independent of , but was significantly increased for cells growing at I <9.4 Wm–2. The half-saturation constant for nitrate uptake (Ksu) increased with increasing , but was independent of the prevailing light conditions. The effects of light during nitrate-limited growth were associated with the regulation in the nitrogen-containing pigments.The results reported herein have important consequences for the use of Q, Ksu and Vmax values as indicators of nutrient-deficiency of natural populations. |
| |
Keywords: | Oscillatoria agardhii Cyanobacterium Chemostat culture Nitrate-limitation Light-nonsaturation Growth kinetics Nitrate uptake kinetics |
本文献已被 SpringerLink 等数据库收录! |
|