TY  - JOUR
A1  - Lachmann, Sabrina C.
A1  - Maberly, Stephen C.
A1  - Spijkerman, Elly
T1  - Species-specific influence of P-i-status on inorganic carbon acquisition in microalgae (Chlorophyceae)
JF  - Botany
N2  - Inorganic phosphorus (P-i) is often the primary limiting nutrient in freshwater ecosystems. Since P(i-)limitation affects energy transduction, and inorganic carbon (C-i) acquisition can be energy demanding, C(i-)acquisition strategies were compared in four species of green algae grown under P-i-replete and P-i-limited conditions predominantly at low and partly at high CO2. Although P-i-limitation was evident by the 10-fold higher cellular C:P ratio and enhanced phosphatase activity, it only decreased C-i-acquisition to a small extent. Nonetheless, the effects of Pi-limitation on both CO2 and HCO3- acquisition were demonstrated. Decreased CO2 acquisition under conditions of Pi limitation was mainly visible in the maximum uptake rate (V-max) and, for the neutrophile Scenedesmus vacuolatus, in the affinity for CO2 acquisition. Discrimination against C-13 was higher under P-i-limited, high CO2 conditions, compared with P-i-replete, highCO(2) conditions, in Chlamydomonas acidophila and S. vacuolatus. In the pH-drift experiments, HCO3- acquisition was reduced in P-i-limited C. reinhardtii. In general, energy demanding bicarbonate uptake was indicated by the less strong discrimination against (13)Cunder lowCO(2) conditions in the neutrophiles (HCO3- users), separating them from the acidophilic or acidotolerant species (CO2 users). The high variability of the influence of Pi supply among different green algal species is linked to their species-specific C(i-)acquisition strategies.
KW  - CCM
KW  - Chlamydomonas
KW  - inorganic carbon uptake kinetics
KW  - inorganic phosphorus limitation
KW  - stable carbon isotope discrimination
Y1  - 2017
U6  - https://doi.org/10.1139/cjb-2017-0082
SN  - 1916-2790
SN  - 1916-2804
VL  - 95
SP  - 943
EP  - 952
PB  - NRC Research Press
CY  - Ottawa
ER  -