Marine polysaccharides for healthcare applications

Thanks to its diversity and complexity, the marine world offers an infinite number of original molecules yet to be discovered. One of the challenges facing research today is to explore marine biodiversity with a view to exploiting it. The study of marine biodiversity, and marine polysaccharides in particular, represents a major challenge for research and biotechnology.

Indeed, thanks to their great structural diversity and specific properties, terrestrial and marine polysaccharides already occupy a sometimes unsuspected but nonetheless important place in our daily lives (food additives, toothpaste, textiles, etc.). As far as polysaccharides are concerned, several sources are already being exploited: terrestrial plants and animals, algae and bacteria. Since 1930, algal polysaccharides have been widely used in the food, cosmetics and pharmaceutical industries, in agriculture and, more recently, in biotechnology. Bacterial polysaccharides are currently the focus of major research and development, including glycosaminoglycans (hyaluronan and heparin precursors) and alginate. Bacterial origin enables us to fully control polysaccharide production and avoid using sources that may contain unconventional transmissible agents and viruses, such as mainly animal sources (porcine and bovine). Since the discovery of deep ocean hydrothermal springs and an exceptional microbial world, strain libraries have been set up to isolate new molecules, such as thermostable enzymes or original polysaccharides.

Polysaccharides are complex macromolecules found in all kingdoms (plant, animal and bacterial). Polysaccharides are made up of strings of osidic units linked by glycosidic bonds. The motif repeated n times, or repeating unit, may be made up of the same monosaccharide (homosaccharide) or several different motifs (heterosaccharide). The polysaccharide can be characterized by this repeating sequence made up of neutral oses (glucose, galactose, xylose, fucose...) or acid oses (glucuronic, galacturonic, iduronic...) or hexosamines (N-acetyl-glucosamine, N-acetyl-galactosamine). Polysaccharides can also be substituted by organic (acetate, lactate, pyruvate, succinate) or inorganic (phosphate, sulfate...) groups. The physico-chemical properties of polysaccharides depend on their molar mass, generally ranging from 100,000 to several million grams per mole, their chemical composition, and finally their structure: linear, branched, with or without substituents, their position and branching. Thanks to their almost infinite structural diversity, each polysaccharide characterized by its repeating unit is unique, and thus offers specific functional properties: thickening, stabilizing or gelling properties already widely exploited in the food and pharmaceutical industries, but also specific biological...