Studies by Microelectrophoretic and Microscopic Techniques of the Sorption of Illite and Montmorillonite to Rhizobia

SUMMARY Electrophoretic measurements indicated that with increasing concentrations of illite or montmorillonite the surfaces of bacteria became progressively enveloped by a layer of adsorbed clay. The amount of clay adsorbed per unit area of cell surface depended mainly on the surface ionogenic properties of the isolates of the Rhizobium species used. For any particular isolate, almost identical amounts of illite and montmorillonite were adsorbed per bacterium. Microscopic studies confirmed the presence of a clay envelope around the bacteria and provided some information on the mode of adsorption of the clays.