Extracellular microbial polysaccharides: Generalized power law for biopolysaccharide solutions

A generalized power low model, {article}{empty}{document}η \, = \,η ₀ [1\, + \,( γ /γ ₀ )]N - 1{document} , is shown to described satisfactorily the shear viscosity data for xanthan gum solutions from 0.18 g/L to nearly 4 g/L and low to intermediate shear rates. Since mixing, mass and heat transfer, residence time distributions, and power input for agitation and aeration all depend on shear viscosity, this equation provides a simple prediction of this important quantity over the shear rate ranges characteristic of fermentations.