| Two kinds of carriers for enzyme immobilization were synthesized. Glucoamylase and penicillin acylase were immobilized onto the carriers respectively. Activity and stability of immobilized glucoamylase and penicillin acylase were studied. The PF gel-type resin has been synthesized by polycondensation of hydroquinone with formaldehyde in the presence of acidic solution. It is an effective carrier for immobilization of various enzymes and proteins. Immobilized glucoamylase can be used repeatedly and continuously for conversion of corn starch, liquefaction through a -amylase to glucose. High activity and good stability were obtained. A series of acrylic acid, acrylamide or acrylonitrile copolymer beads crosslinked with divinyl benezene were synthesized by suspension polymerization. The continuous phase was 34% aqueous solution of calcium chloride, the discontinuous organic phase was composed of monomer and crosslinking agent and poregenerating solvent, petroleum ether(b.p.90-120扖). The initiator, benzoyl peroxide, were added to the monomer prior to suspension. The amount of binding protein onto these carriers were determined. It is showed that the acrylic acid-divinyl benzene copolymer was the most effective carrier for binding of bovine serum albumin. Penicillin acylase was immobilized onto this carrier to convert benzylpenicillin to 6-aminopenicillanic acid, which may be employed in the manufacture of semi-synthetic penicillins. The optimum conditions of immobilized penicillin acylase, such as temperature, pH and amount of native enzyme, were studied. Under optimum experimental conditions, the activity and activity recovery of immobilized enzyme were determined. At 40扖 and pH 8.0, the value of kinetic Michaelis-Menten constant of the immobilized enzyme(K~~) was determined. The value of apparent activation energy of enzyme catalysis was determined, too.
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