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

Mabeau, S. and Kloareg, B. 1987. Isolation and analysis of thecell walls of brown algae: Fucus spiralis, F. ceranoides, F.vesiculosus, F. serratus, Bifurcaria bifurcata and Laminariadigitata.—J. exp. Bot. 38: 1573–1580. Cell walls were isolated from six marine brown algae, Fucusspiralis, F. ceranoides, F. vesiculosus, F. serratus, Bifurcariabifurcata (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 alginatesand sulphatcd fucans, the proportions of which correlated withspecies zonation in the intertidal region. This result is consistentwith the hypothesis that the sulphated fucans are associatedwith the adaptation of macroalgae to the intertidal environment.Comparing the chemical composition of isolated cell walls withthat of whole plants, we conclude that alginic acid is mainlypart of the fibrillar wall while a significant proportion ofthe sulphated fucans probably belongs to the intercellular spacematrix. Since ascophyllan-like polysaccharides were more abundantin the fucan extracts from the isolated cell walls than fromthe whole plants, it is suggested that differences in the structureof fucans might be related to differences in their localizationthroughout the tissue. Key words: Cell walls, Phaeophyta, sulphated fucans