@article{LachmannMaberlySpijkerman2017, author = {Lachmann, Sabrina C. and Maberly, Stephen C. and Spijkerman, Elly}, title = {Species-specific influence of P-i-status on inorganic carbon acquisition in microalgae (Chlorophyceae)}, series = {Botany}, volume = {95}, journal = {Botany}, publisher = {NRC Research Press}, address = {Ottawa}, issn = {1916-2790}, doi = {10.1139/cjb-2017-0082}, pages = {943 -- 952}, year = {2017}, abstract = {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.}, language = {en} }