| 摘要 |
PURPOSE:To re-immobilize an enzyme, by removing the enzyme together with a water soluble high polymer from an enzyme immobilizing membrane reduced in productivity, re-impregnating the water soluble high polymer from the porous material side of the above-mentioned membrane, cross-linking the high polymer with an aqueous crosslinking agent and permeating an aqueous enzyme solution. CONSTITUTION:A membrane material such as polysulfone membrane or the like is dissolved in a polar organic solvent mixable with water, brought into contact with a solidifying solution mainly consisting of water to provide an anisotropic ultrafiltration membrane having dense layer and porous layer. A water soluble high polymer such as polyethylene imine or the like having at least two functional group is impregnated into the above-mentioned filtration membrane under pressure condition, crosslinked with a crosslinking agent such as dialdehydes or the like and the remaining uncrosslinked water soluble high polymer is removed and an enzyme is permeated from the porous layer side and covalently linked with the polymer through the functional group of the polymer. Further an aqueous sodium hypochlorite solution (effective chlorine concentration; 500-1,000ppm) and hydrochloric acid (concentration of 0.005-0.05N) are permeated from the dense layer side of the enzyme immobilizing membrane to the porous layer side to remove the enzyme and the water soluble high polymer and the enzyme can be re-immobilized in the same way.
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