Alginate is extracted from brown algae and some bacteria. It is an abundant natural polysaccharide and usually exists as sodium salt. In this book, the authors present topical research in the study of the production, types and applications of alginate. Topics discussed include the application of alginates in cell and enzyme immobilization; alginate based materials in environmental applications; cross-linked alginates for modified drug delivery applications; bacterial alginate production by fermentation and the preparation and functionalization of alginate-based hydrogels.