Gellan gum, an anionic polysaccharide, is employed as a replacement for agar in various clinical bacteriological and plant tissue culture media. Its structural composition comprises a repeating tetrasaccharide unit, including two D-glucose residues, one L-rhamnose residue, and one D-glucuronic acid residue. It is an excellent alternative for nutrient media in plant tissue culture, yielding a clearer and more transparent gel than agar. Additionally, it requires only half the concentration of agar typically used in tissue culture media.