Microbial exopolysaccharides (EPSs) are structurally diverse, high-molecular-weight biopolymers that underpin microbial survival and offer a broad range of biotechnological applications. EPSs are secreted by diverse microorganisms and form the structural and functional core of extracellular matrices, where they mediate adhesion, stress tolerance, and nutrient acquisition. This review critically synthesizes recent advances in EPS research with a dual focus on their roles in microbial fuel cells (MFCs) and their expanding applications in bioremediation, sustainable agriculture, green nanomaterial synthesis, and medicine. Notably, EPS-enriched biofilms have demonstrated improvements in MFC power densities ranging from 60 to 150 mW m− 2 and increases in anodic current densities of 20–80%, underscoring their electrochemical importance. Unlike prior reviews, this review integrates microbial ecological insights with engineering perspectives, evaluating EPS as both biofilm-stabilizing matrices and redox-active mediators. A critical focus is placed on commercialization hurdles, including scale-up, purification, and unresolved structure–function gap. Furthermore, EPS-mediated applications are used in heavy metal bioremediation, sustainable agriculture, green nanomaterial synthesis, and advanced drug delivery systems. A central theme of this review is the identification of critical challenges that currently hinder widespread commercialization, especially the lack of standardized large-scale production and purification methods and the poorly resolved structure-function relationships that impede rational EPS design. This review concludes that while significant progress has been made, future breakthroughs will require coordinated efforts in microbial engineering, bioprocess optimization, and molecular characterization to enable scalable, application-specific production to successfully attain a complete and true circular bio-economy.
Singh et al. (Wed,) studied this question.