Types of microbial polysaccharides and their characterization

Microbial polysaccharides, essential in cellular structures, are versatile natural polymers with increasing significance compared to traditional seaweed sources. Derived from bacteria, fungi, and microalgae, these polysaccharides offer advantages like high yields, quality, biocompatibility, and structural diversity, finding applications in various industries. Of particular interest are exopolysaccharides (EPSs), swiftly isolated from microorganisms, serving as defense mechanisms and contributors to symbiotic relationships in response to environmental factors. Microbial EPSs are important for hydrogel formation and have applications in food, biomedical, and environmental sectors. In the food industry, they enhance quality and shelf life, functioning as emulsifiers, stabilizers, and cryoprotectants. In biomedical applications, microbial polysaccharides play pivotal roles in delivering drugs, wound healing, and tissue engineering, offering diverse health-related properties. This review navigates through the functions of microbial polysaccharides, addressing production cost challenges through sustainable methods, and exploring combinations with proteins or chemical modifications. This review specifically explores three key microbial polysaccharides—xanthan, pullulan, and dextran-providing detailed insights into their structures, sources, properties, biosynthesis, industrial production, characterization, and versatile applications.