title: Use of polyelectrolyte complex-stabilized calcium alginate gel for entrapment of beta-amylase.
abstract: Calcium alginate gel stabilized with a polyelectrolyte complex (PEC) consisting of potassium poly(vinyl alcohol) sulfate (KPVS) and trimethylammonium glycol chitosan iodide (TGCI) was used for the immobilization of beta-amylase. The immobilization was made by gelling aqueous droplets of enzyme solution including both sodium alginate and KPVS in a CaCl(2) solution containing TGCI. The activity of the enzyme entrapped into the stabilized gel beads was evaluated by studying the batch reaction kinetics of enzyme-catalyzed hydrolysis of maltotetraose. Repeated kinetic measurements, totaling 18, were carried out at fixed time intervals. After each measurement the beads were stirred for 1 day in a freshly prepared 10 mM NaCl solution at 3 degrees C. It was found that the immobilized system remained stable without leading to a serious loss of the activity or to a large leakage of the enzyme from the support. This was explained as being due to a PEC-crosslinked contracted network structure of the stabilized gel matrix.
authors.affiliation: Institute of Applied Biochemistry, University of Tsukuba, Sakura-mura, Niihari-gun, Ibaraki 305, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Kokufuta
authors.forename: N
authors.initials: N
authors.lastname: Shimizu
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: I
authors.initials: I
authors.lastname: Nakamura