Abstract: Aminated macroporous PVC bead was used as carrier to prepare immobilized papain samples by glutaraldehyde through crosslinking reaction. The hydrolytic activity of the immobilized papain was determined using casein as substrate. The factors affecting the activity of immobilized papains such as reaction tirne,temperature,pH,amount of papaln and concentration of glutaraldehyde were studied. The immobilized papain has a remarkable increase in the stability and better reuse ability than natural papain.

Key words: papain, aminated PVC, immobilized enzyme