Gellan

Bacteria of the species Sphingomonas paucimobilis, strain ATCC 31461 and formerly known as Pseudomonas elodea, secrete gellan, an exopolysaccharide built from a tetrasaccharide repeating unit of glucose, rhamnose and glucuronic acid in a 2:1:1 ratio, with acyl substitution on one glucose. In the presence of cations it sets into clear, brittle gels, which is why foods use gellan gums as gelling agents and thickeners. Confectionery, dairy desserts and plant milks exploit its heat-stable, flavour-releasing gels, and tiny doses suspend particles in beverages without clouding them.