The United States of America As Represented by the Secretary of

Virginia G Randall

Merle S Masri

William L Stanley

Insolubilized but active enzymes are prepared in a variety of ways. In one embodiment of the invention an aqueous solution of an enzyme is mixed with chitosan dissolved in water at pH 3-7 and an insolubilized product is precipitated therefrom by addition of alkali or a source of sulfate ions. Another embodiment of the invention involves contacting solid chitosan sulfate with an aqueous solution of the enzyme to be immobilized. In yet another embodiment of the invention solid chitosan is cross-linked with a polyfunctional cross-linking agent and then contacted with an aqueous solution of an enzyme. Enzymes insolubilized in accordance with the invention retain a substantial part of their original activity.

Method for insolubilizing enzymes on chitosan

Superoxy-anion-forming metals, such as chromium, manganese, and the like, are removed from materials containing the same by contacting the material with an anionically-modified, nitrogen-containing polymer, such as sulfite-modified, sulfate-modified, or chloride-modified chitosan.

Chitosan modified with anionic agent and glutaraldehyde

Insolubilized but active enzymes are prepared by mixing an aqueous solution of the enzyme with a modified phenolic polymer. The phenolic polymer is modified by introducing into the polymer chain either aldehyde groups or diazonium salt groups. The so-produced enzyme products retain a substantial part of the original enzyme activity.

Insolubilization of enzymes on modified phenolic polymers

Insolubilized but active enzymes are prepared by mixing an aqueous solution of the enzyme with an aqueous solution of chitosan and then adding a polyfunctional cross-linking agent to form a gel. The so-produced gel is reacted with a reducing agent to form a granular insolubilized enzyme, which has retained a substantial part of its original activity.

Growing community of inventors

El Cerrito, CA, United States of America

Virginia G Randall