Bacterial polysaccharides are complex carbohydrates produced by bacteria. They serve various functions, including energy storage and structural support. These polysaccharides can be found in the bacterial cell wall or secreted into the environment, forming biofilms or capsules that protect the bacteria from environmental stresses and immune responses. Many bacterial polysaccharides are important in biotechnology and medicine. For example, dextran is used in medical applications, while alginate is utilized in food and pharmaceutical industries. Understanding these polysaccharides can lead to advancements in drug delivery systems and the development of new materials.