Brent Cornell

    
Immobilised enzymes have been fixed to a static surface in order to improve the efficiency of the catalysed reaction

• Enzyme concentrations are conserved as the enzyme is not dissolved – hence it can be retained for reuse
• Separation of the product is more easily achieved as the enzyme remains attached to the static surface

Immobilised enzymes are utilised in a wide variety of industrial practices:

• Biofuels – Enzymes are used to breakdown carbohydrates to produce ethanol-based fuels
• Medicine – Enzymes are used to identify a range of conditions, including certain diseases and pregnancy
• Biotechnology – Enzymes are involved in a number of processes, including gene splicing
• Food production – Enzymes are used in the production and refinement of beers and dairy products
• Textiles – Enzymes are utilised in the processing of fibres (e.g. polishing cloth)
• Paper – Enzymes assist in the pulping of wood for paper production

Common Industrial Uses of Enzymes

    
Lactose is a disaccharide of glucose and galactose which can be broken down by the enzyme lactase

Historically, mammals exhibit a marked decrease in lactase production after weaning, leading to lactose intolerance

• Incidence of lactose intolerance is particularly high in Asian, African and Aboriginal populations
• Incidence is lower in European populations (due to a mutation that maintains lactase production into adulthood)

Breakdown of Lactose by the Enzyme Lactase

Producing Lactose-Free Milk

Lactose-free milk can be produced by treating the milk with the enzyme lactase

• The lactase is purified from yeast or bacteria and then bound to an inert substance (such as alginate beads)
• Milk is then repeatedly passed over this immobilised enzyme, becoming lactose-free

Scientists are currently attempting to create transgenic cows that produce lactose-free milk

• This involves splicing the lactase gene into the cow’s genome so that the lactose is broken down prior to milking

Generation of Lactose-Free Milk Using Immobilised Enzymes

Advantages of Lactose-Free Dairy Products

The generation of lactose-free milk can be used in a variety of ways:

• As a source of dairy for lactose-intolerant individuals
• As a means of increasing sweetness in the absence of artificial sweeteners (monosaccharides are sweeter tasting)
• As a way of reducing the crystallisation of ice-creams (monosaccharides are more soluble, less likely to crystalise)
• As a means of reducing production time for cheeses and yogurts (bacteria ferment monosaccharides more readily)