Читать книгу Polysaccharides - Группа авторов - Страница 60

Alginates, a common name for alginic acid salts, is a category of anionic polysaccharides occurring primarily in brown marine algae (species belonging to Laminaria, Macrocystis, Ascophyllum, Sargassum) and other bacterial organisms (such as Pseudomonas, Azotobacter) [26, 27]. Bacterial alginates can be secreted by the strains as extra cellular material. However, at present, commercial alginate is derived from farmed brown seaweeds, since they can contain up to 40% (w/w) alginates in the form of an intracellular gel complexed with ions such as calcium, magnesium, and sodium [28, 29]. These are 1,4-linked linear polymers of β-D-mannuronic acid and α-L-guluronic acid [30]. In the midst of crosslink divalent (namely Ca, Ba and Sr) ions, alginates can form transparent gels that play an important role in nutrition and medicines.