A Critical Review of the Microbial Exopolysaccharide Xanthan

P. Wintersteller, A. Huber and M. Koller

Abstract
Xanthan gum, a microbial exopolysaccharide produced by Xanthomonas campestris, exhibits exceptional rheological behavior, structural versatility, and environmental resilience, making it indispensable across food, pharmaceutical, cosmetic, and industrial sectors. This review critically examines its biosynthesis, molecular configuration, and physicochemical properties, with emphasis on how cultivation parameters and polymer architecture influence its functionality. It highlights the role of side chain composition, ion interactions, and macromolecular conformations in determining xanthan’s unique pseudoplasticity and stability. The paper further explores advancements in novel feed stocks and sustainable production techniques. Future research directions are identified, including enhanced control of structure-function relationships, enzyme-based modifications, and xanthan’s role in emerging fields like 3D bioprinting and biodegradable materials. Overall, xanthan gum is positioned as a model hydrocolloid for both current industrial use and future innovation in biomaterials science.

This work is licensed under a Creative Commons Attribution 4.0 International License

Keywords
xanthan gum, microbial exopolysaccharide, rheological properties, industrial applications, biopolymer, biosynthesis