Binding of Colloidal MnO 2 by Extracellular Polysaccharides of Pedomicrobium manganicum

Abstract

The extracellular acidic polysaccharides of the manganese-oxidizing bacterium Pedomicrobium manganicum were able to bind preformed colloidal MnO 2 . The capacity of the cells to bind MnO 2 was pH dependent. Enhanced binding capacity below pH 5 suggests that ionic bonding forces are involved in the binding mechanism and that there is a charge reversal on the acidic polysaccharides between pH 5 and 4 that is due to increased protonation of carboxyl groups.