Enzyme Immobilization

Enzyme engineering is a fast-growing application in the pharmaceutical market. Enzymes are key to new processes because they are environmentally friendly and reduce hazardous waste. Enzymatic reactions can occur under milder conditions, at a faster rate, while being highly specific. Therefore, enzymatic process allows to minimize process steps.

Enzymes can be operated in the liquid form or immobilized on various supports. Immobilized enzymes enhance process robustness, allow longer duration of activity of enzymes, and re-use of the same enzymes in multiple cycles.

Process design gains flexibility thanks to the different modes of operation: batch or column. Further more, the use of immobilized enzyme eliminate the enzyme separation step from the main process thus simplifying and increasing the overall process yield.

The main advantages of immobilized enzymes are:

• Easy separation from reaction mixture, providing the ability to control reaction times and minimize the enzymes lost in the product.
• Re-use of enzymes for many reaction cycles, lowering the total production cost of enzyme mediated reactions.
• Ability of enzymes to replace multiple standard chemical steps and provide enatomerically pure products.

Methods of fixation

Three main modes of operation are currently used with enzymes. From simple absorption, ionic to covalent binding. These modes of operation allow a wide range of enzyme and applications to be covered.

• Simple adsorption onto a hydrophobic resin.
• Adsorption onto a resin followed by glutaraldehyde crosslinking.
• Ionic bonding (with H₊ or OH_- form resins).
• Covalent bonding via -NH₂ groups.
• Via enzyme cofactors such as Fe, Ni, Al etc.