Magnetic particles as supports in immobilised enzyme reactors

Enzymes are immobilised to a wide range of support materials so that their catalytic activity can be re-used in biological reactors. Magnetic support particles have the potential for extending immobilised enzyme technology to new areas of industrial use. The enzyme α-chymotrypsin has been immobilised to several particulate magnetic materials. Uncoated metal and metal oxide powders are unstable in acidic solutions. Even in neutral solutions metal ions from an uncoated particle surface inhibited α-chymotrypsin giving a rapid decline in activity. The rate of loss of activity was greatly reduced by coating the magnetic particles with a thin layer of bovine serum albumin before immobilising the enzyme to them. Reactor designs are proposed using magnetic coolant filters or high gradient magnetic separators to remove the magnetic immobilised enzyme particles from the product stream so that they can be returned to the reactor.