| Sphingan, a class of biopolymers with high-molecular-weight exopolysaccharides synthesized as secondary metabolites by Sphingomonas species, has garnered considerable attention due to their versatile functional properties and wide-ranging applications. This review offers a comprehensive exploration of the structure-function relationships of three representative sphingans, including Gellan Gum, Welan Gum, and Sanxan Gum, with a focus on their unique rheological behavior, gelation mechanisms, and bioactive characteristics. The influence of environmental factors, such as temperature, pH, and ionic composition, on their physicochemical properties is systematically analyzed, providing insights into their adaptive functionalities. To address production scalability challenges, this review outlines critical strategies for enhancing sphingan biosynthesis, encompassing strain improvement through mutagenesis and genetic engineering, metabolic pathway optimization, and fermentation intensification. A promising avenue for sustainable production is the utilization of agricultural and industrial waste streams as alternative carbon sources, which not only reduces costs but also aligns with circular economy principles. Furthermore, the review examines the applications of sphingans in food, pharmaceuticals, agriculture, and the petroleum industry, highlighting their broad industrial relevance. Future research directions are proposed, focusing on structural modifications, functional enhancements, and innovative applications in emerging high-value sectors. This review provides a comprehensive understanding of sphingans, connecting fundamental insights with practical advancements, and offers a foundation for their broader commercialization and application. |
