enzymes in industry

• One use of enzymes in industry is-

  1. Batch reactor.

  The enzyme and substrate are dissolved are can mix in a solution

  The batch reaction is a simple way of getting a product made (like baking)
• Drawback of the batch reactor

  its contaminated, takes alot of time to complete and is expensive
• In the column reactor, substrate molecules again are dissolved in a solution. They flow past enzymes that are physically attached with a type of inert support material. This does not dissolve in solvent use.

  It allows continuous flow of substrate across material holding the enzyme so is also called the CONTINUOS FLOW COLUMN REACTION
• A drawback to column reactor


  Has to be a liquid
• Advantage to column reactor

  Can run continuosly
• What are advantaged of immobilisation?

  1. immobilised enzymes are physically combined with reactor so can be used continuously which is good as its cost effective
  2. final product is not contaminated with enzyme. therefore not costly, not time consuming purification needed.
  3. prevents disruption of tertiary structure so enzymes active site not ruined by temp and/or pH. This is good as reactions can run at higher temperatures.
• enzymes are thermostable
• Disadvantages of immobilisation:

  Diffusion into supporting material is slower as the continuous flow may make it less likely the substrate molecules will bind with enzymes. This means there is a slower rate of formation of ES complex formation and a reduced rate of reaction.

  Not all enzyme is available as some active sites are orientated (random- some fixed in some fixed out) into the supporting material so cant get to active site.

  Active sites may be slightly altered by immobilisation thus substrate

  binding is made more difficult due to a slower rate of reaction.
• Enzymes are often added to washing powders because they speed up hydrolysis of stains on clothes.
• The most common stain remover is protease.
• Protease breaks down protein based stains such as blood or grass.
• Proteases work best under alkaline conditions.
• Washing powder contains an alkali like sodium carbonate to raise the pH of water making it alkaline.
• Sodium carbonate activates the protease.
• The protease then cleaves peptide bonds breaking down the protein stain.
• The protease is usually immobilized onto the surface of the washing powder granules to make it easier to remove from clothing when rinsed off.
• If the enzyme was free in solution it would be washed away during the wash cycle.
• methods of immobilising enzymes:

  1. Entrapment
  2. Absorption
  3. Encapsulation
  4. Cross Linkage
• Immobilising enzymes through the process of absorption is when enzyme are attached by weak forces to a inert substance e.g. glass (porous) on a matrix.
• Immobilising enzymes through the process of Entrapment, which happens from when enzymes are trapped within polymers e.g. alginate beads or microspheres.
• Immobilising enzymes through the process of Encapsulation happens when enzymes are trapped inside a selectively permeable membrane (enzyme cant get out, substrate can get in) such as nylon.
• Immobilising enzymes through the process of Cross Linkage happens when enzymes are covalently bonded to a MATRIX e.g. cellulose as a consequence of a chemical reactions
• Properties of material used for enzyme immobilisation:

  ● Must be inert

  ● Must be permeable to allow substrate and product to pass through it if entrapment is being used

  ● Must be permeable to enzyme if entrapment is being used (has to be able to get in, but then is locked in)

  ● Insoluble in nature so that the enzyme can be recovered (you don't want matrix dissolving while using it so you need to be able to recover it)
• Examples of immobilised enzymes:

  Clinistix where the enzyme (glucose oxidase) is attached by adsorption or covalent bonding to a solid support.
• Uses of enzymes:

  ● Amylases in malting