The environmental role of alginates in Durvillaea potatorum (Fucales, Phaeophyta)

Abstract

The composition of alginates and their contribution to the dry wt of the lamina and stipe of D. potatorum were examined. Assays of tissue samples were performed using the carbazole method and standards for these assays were prepared by partial acid hydrolysis of extracted alginates followed by differential precipitation of the fractions. The compositions of the standards were determined using high field 13C NMR spectroscopy. The lamina and stipe contain alginates rich in mannuronic acid, whereas the holdfast tissue is rich in guluronic acid. This variation in alginate composition is probably related to the function of the tissues in terms of providing flexibility for the lamina and stipe, and rigidity to the holdfast.