Abstract: Synthetic method of immobilized Neutrase enzyme prepared by reacting glutaraldehyde with chitosan was studied. Thee ffectso fc hitosanc oncentration,a dditiono f glutaraldehyde andc rosslinking timeo n preparationo fb eadsa nd onc oncentration of glutaraldehyde immobilization were analysed. Through perpendicular experiment, the optimized conditions of immobiliza- tionw ered etermineda s follows: chitosan concentration3 %,m olr ationo f glutaraldehydea ndg lucosaminer esidue1 :2,c rosslinking time 1h for preparation of chitosan beads, and adsorption time 12h. The final concentration of 2.5% glutaraldehyde was 0.9%. The activity of the immobilized Neutrase prepared under the optimal conditions was 112.69U/g. The thermostability and pH stability of immobilized enzyme were higher than those of soluble enzyme.

Key words: chitosan, neutrase, immobilized