An M(III)-facilitated flocculation technique for enzyme recovery and concentration

An inexpensive and rapid flocculation/dissolution technique based upon Al(III) or Fe(III) was shown to be effective in recovering and concentrating up to 84% of the active enzyme from two dilute enzyme systems. The enzymes, a protease (Caldolysin) and a beta-glucosidase, were precipitated at constant pH and ambient temperature by addition of Fe(III) or Al(III) solutions. Resulting colloidal hydrous oxide particles bound the enzymes enabling subsequent separation from the media by low speed centrifugation. The enzymes were recovered from the protein/M(III) precipitate by complexing the M(III) with citrate. A concentration factor of 94 was obtained for the beta-glucosidase system when the initial concentration was less than 1 mg.ml-1.