Ecophysiology matters: linking inorganic carbon acquisition to ecological preference in four species of microalgae (Chlorophyceae). Issue 6 (24th October 2016)

• Record Type: Journal Article
• Authors: Lachmann, Sabrina C.; Maberly, Stephen C.; Spijkerman, Elly
• Editors: Raven, J.
• Is Part Of: Journal of phycology. Volume 52:Issue 6(2016:Dec.)
• Page Start: 1051
• Page End: 1063
• Publication Date: 2016-10-24
• Subjects: acidophile -- carbon acquisition -- CCM -- Chlamydomonas -- Chlorella -- CO2 supply -- extremophile -- inorganic carbon uptake kinetics -- pH‐drift -- Scenedesmus; Algae -- Periodicals; 579.8
• DOI: 10.1111/jpy.12462
• Languages: English
• ISSNs: 0022-3646

Abstract

Abstract : The effect of CO2 supply is likely to play an important role in algal ecology. Since inorganic carbon (Ci ) acquisition strategies are very diverse among microalgae and Ci availability varies greatly within and among habitats, we hypothesized that Ci acquisition depends on the pH of their preferred natural environment (adaptation) and that the efficiency of Ci uptake is affected by CO2 availability (acclimation). To test this, four species of green algae originating from different habitats were studied. The pH‐drift and Ci uptake kinetic experiments were used to characterize Ci acquisition strategies and their ability to acclimate to high and low CO 2 conditions and high and low pH was evaluated. Results from pH drift experiments revealed that the acidophile and acidotolerant Chlamydomonas species were mainly restricted to CO2, whereas the two neutrophiles were efficient bicarbonate users. CO2 compensation points in low CO 2 ‐acclimated cultures ranged between 0.6 and 1.4 μM CO2 and acclimation to different culture pH and CO2 conditions suggested that CO2 concentrating mechanisms were present in most species. High CO 2 acclimated cultures adapted rapidly to low CO2 condition during pH‐drifts. Ci uptake kinetics at different pH values showed that the affinity for Ci was largely influenced by external pH, being highest under conditions where CO2 dominated the Ci pool. In conclusion, Ci acquisition was highly variable among four species of green algae and linked to growth pH preference, suggesting that there is a connection between Ci acquisition and ecological distribution.