Ion-Exchange Properties of Isolated Cell Walls of Brown Algae: The Interstitial Solution

Abstract

Kloareg, B., Demarty, M. and Mabeau, S. 1987. Ion-exchange properties of isolated cell walls of brown algae: the interstitial solution.—J. exp. Bot. 38: 1652-1662. Isolated cell walls of Pelvetia canaliculata (Dene) et Thur., Laminaria digitata (L.) and other intertidal brown algae were equilibrated in seawater and various mixtures of sodium and calcium chlorides. After elution with distilled water, the interstitial solution was assayed for ionic composition. With respect to the external solution, it was less concentrated and contained lower proportions of divalent cations. Such modifications were related to the divalent ionic fraction and the total anion con centration of the external solution. No significant differences were found among the brown algae investigated in spite of the differing composition of their walls. Results were analysed according to the polyelectrolyte condensation model. When the concentration of the external solution was high (1000 meq dm ~ 3), experimental data were qualitatively in good agreement with the predictions of the model.