Isolation and Analysis of the Cell Walls of Brown Algae:Fucus spiralis, F. ceranoides, F. vesiculosus, F. serratus, Bifurcaria bifurcataandLaminaria digitata

Abstract

Mabeau, S. and Kloareg, B. 1987. Isolation and analysis of the cell walls of brown algae: Fucus spiralis, F. ceranoides, F. vesiculosus, F. serratus, Bifurcaria bifurcata and Laminaria digitata.—i. exp. Bot. 38: 1573-1580. Cell walls were isolated from six marine brown algae, Fucus spiralis, F. ceranoides, F. vesiculosus, F. serratus, Bifurcaria bifurcata (Fucales, Phaeophyta) and Laminaria digitata (Laminariales, Phaeo phyta). Yields of isolated cell walls ranged from 35-45% of thallus dry weight. Walls were composed mainly of alginates and sulphated fucans, the proportions of which correlated with species zonation in the intertidal region. This result is consistent with the hypothesis that the sulphated fucans are associated with the adaptation ofmacroalgae to the intertidal environment. Comparing the chemical composition of isolated cell walls with that of whole plants, we conclude that alginic acid is mainly part of the fibrillar wall while a significant proportion of the sulphated fucans probably belongs to the intercellular space matrix. Since ascophyllan-like polysaccharides were more abundant in the fucan extracts from the isolated cell walls than from the whole plants, it is suggested that differences in the structure of fucans might be related to differences in their localization throughout the tissue. Key words—Ce 11 walls, Phaeophyta, sulphated fucans. Correspondence to: Centre d'Etudes Oceanologiques et de Biologie Marine, CNRS, LP 4601, Place