Adsorption of colloidal hydrous alumina on yeast cells

Abstract

The adsorption of synthetic colloidal (0.25 µm) spherical hydrous alumina particles on cells of the yeast Saccharomyces cerevisiae(5.7 µm) was studied at very low ionic strength in a stirred system. A kinetic study shows that apparent adsorption equilibrium requires ca. 15 h. The Langmuir-type adsorption isotherm is the same for pH 4, 6 and 8; the plateau corresponds to 75% coverage of the yeast cells by the adhering alumina particles, assuming a close-packed hexagonal array for the complete coverage. The presumed influence, on both the adsorption kinetics and the isotherm, of the aggregation of composite particles, consisting of a collector particle and adsorbed particles, is emphasized.