Welan gum is an exopolysaccharide used as a rheology modifier in industrial applications such as cement manufacturing.[1] It is produced by fermentation of sugar by bacteria of the genus Alcaligenes. The molecule consists of repeating tetrasaccharide units with single branches of L-mannose or L-rhamnose. In solution, the gum exhibits viscosity retention at elevated temperature, and is stable in a wide pH range, in the presence of calcium ion, and with high concentration of glycols.