immobilised enzymes

• what are four ways used to immobilise enzymes?

  • surface immobilisation- adsorption to inorganic carriers
  • surface immobilisation- covalent/ionic bonding to inorganic carriers
  • entrapment in a matrix
  • entrapment within a membrane using microcapsules (encapsulation) or behind a semi-permeable membrane
• what are the advantages of using immobilised enzymes?

  • can be reused- cheaper
  • more reliable- high degree of control over process as insoluble support provides stable microenvironment for immobilised enzymes
  • can be manipulated- eg be made to suit a process easier than free enzymes- can be used for a longer period of time at higher temps, reducing cost
  • easily separated from reactants and products- less downstream processing
• what are the disadvantages of using immobilised enzymes?

  • reduced efficiency- reduced activity rate
  • immobilised enzymes are more expensive than free enzymes
  • higher cost of bioreactor- initial investment cost as the system needed is different from traditional fermenters
  • more technical issues- reactors are more complex than other simpler ones- more things can break down/go wrong
• what is meant by immobilised enzymes?

  enzymes stuck to a inert support system or surface/held stationary while the reaction is taking place and substrate passes over enzyme. Because the are held stationary, they can be reused again as they are not lost