Advances in fermentative production, purification, characterization and applications of gellan gum

Multiple microbial exopolysaccharides have been reported in recent decade with their structural and functional features. Gellan gum (GG) is among these emerging biopolymers with versatile properties. Low production yield, high downstream cost, and abundant market demand have made GG a high cost material. Hence, an understanding on the various possibilities to develop cost-effective gellan gum bioprocess is desirable. This review focuses on details of upstream and downstream process of GG from an industrial perspective. It emphasizes on GG producing Sphingomonas spp., updates on biosynthesis, strain and media engineering, kinetic modeling, bioreactor design and scale-up considerations. Details of the downstream operations with possible modifications to make it cost-effective and environmentally sustainable have been discussed. The updated regulatory criteria for GG as a food ingredient and analytical tools required to validate the same have been briefly discussed. Derivatives of GG and their applications in various industrial segments have also been highlighted.