Design of Ca-alginate immobilized yeast cell beads with controlled low density to enhance their fluidization behaviour in bioreactors

The incorporation of small glass hollow spheres into Ca-alginate beads allows the density of immobilized cell preparations to be decreased. For immobilized yeast, glass hollow spheres at 14% (v/v) decrease the density from 1088 to 996 kg m-3, thus greatly changing their hydrodynamic properties. As a consequence, the operation of a three-phase fluidized bed reactor is clearly improved. © 1993 Science & Technology Letters.