Abstract: Dust free enzyme containing particles are produced by coating hydratable core particles with an enzyme and then with a film-forming macro-molecular material. Coating is carried out by suspending the core particles in a fluidized bed dryer, spraying an aqueous slurry of enzyme onto the core particles while suspended, and evaporating water to leave a dried enzyme coat on the particles. The resultant enzyme-coated particles, while still suspended in the fluidized bed, are sprayed with a solution or dispersion of the macro-molecular material, and dried to remove solvent to leave a coating of the macro-molecular material.

Abstract: Spherically shaped bacterial cell aggregates are produced by spheronizing extruded flocculated cells. The cells are flocculated from aqueous medium with a cross-linked polyamine which is the reaction product of an epihalohydrin/polyamine copolymer and a cross-linking agent. Prior to being extruded, a filter cake having 68 to 76 weight percent water is produced by filtration of the flocculated cells, and the filter cake is ground into particles no greater than 60 mesh. Spheronizing is with a plate rotating at a tangential velocity of 4.5 to 12 meters per second within a cylinder containing the plate. Toughness of the spherical aggregates produced can be increased by the addition of a binder after filtration and before extrusion. During spheronizing, fines may be produced. These fines can be recycled by mixing them with the wet filter cake and binder before extrusion.