alpha-Chymotrypsin and acid phosphatase have been immobilized on chitosan, a polyaminosaccharide, without using any intermediate reagent; the immobilized enzymes are active and their activity is much higher than for chitin-immobilized enzymes. The best pH conditions for operating chitosan columns have been determined and columns have been used to transform substrates in large amounts, with no decrease of activity or enzyme losses. Due to the nonconvalent interaction between chitosan and enzymes, the pure and active enzymes can be eventually recovered from the columns. The effects of metal ions, aldehydes, and salts are reported and discussed. Applications are foreseen in the food and biomedical sciences and industries.

Immobilized enzymes on chitosan columns: alpha-chymotrypsin and acid phosphatase.

The ideal enzyme support should show high affinity to proteins, availability of reactive groups for direct reactions with proteins or for chemical modifications, easiness of preparing in different physical forms, nontoxicity and physiological compatability if required (food industry, biomedicine), as well as low cost. Chitin and its derivatives fullfil most of these requirements. The paper reviews enzymes immobilized on chitin and its derivatives along with techniques applied for their immobilization.

Chitin and its derivative as supports for immobilization of enzymes

Popular matrices for enzyme and other immobilizations

Publisher Summary Enzymes immobilized on or within a solid matrix by conjugation with synthetic water-insoluble polymeric supports can serve as reusable and removable highly specific reagents, which possess improved storage and operational stability. Continuous large-scale processes can be carried out in immobilized-enzyme reactors. Immobilized enzymes in conjunction with a detector have led to the development of highly specific electrode systems and similar analytical and monitoring devices. Immobilized enzymes are being explored for clinical application in the form of extracorporeal shunts or microcapsules. The clarification of some of the principles underlying the kinetic behavior of immobilized enzyme systems, that is, effects of the microenvironment imposed by the chemical nature of the support material and the effects of diffusional restrictions on the translocation of substrate and product, make possible the modulation of the properties of a bound enzyme by its conjugation to a support of predetermined chemical and physical characteristics.

The Chemistry of Enzyme Immobilization

Application of living immobilized cells to the acceleration of the continuous conversions of ethanol (wort) to acetic acid (vinegar)—Hydrous titanium(IV) oxide-immobilized Acetobacter species

C.E. Doyle

Papers

Active, water-insoluble derivatives of D-glucose oxidase and alginic acid, chitin, and Celite.