Bioprocessing with Immobilised Enzymes - Revision Notes

Bioprocessing

• Bioprocessing: The use of enzyme-controlled reactions to produce products.
• Bioreactor: A vessel where bioprocessing occurs.
• Used by pharmaceutical and food companies for cost-effective, high-quality production.
• Examples:
  • Cheese making: Rennin coagulates milk.
  • Washing powders: Proteases break down protein-based stains.
  • Alcohol production: Yeast ferments sugar to produce alcohol.

Immobilised Enzymes

• Definition: Enzymes attached to an inert material, fixed in place for reuse.
• Benefits:
  • Saves money and resources in industrial processes.

Methods of Enzyme Immobilisation

1. Attaching enzymes to each other: Linking enzymes together.
2. Binding to inactive substances: Using supports like beads.
3. Trapping in gels or membranes: Encasing enzymes in a gel or film.

How it Works

• Substrate passes over immobilised enzymes.
• Reaction occurs and the product is collected.
• Enzymes remain fixed and reusable.

Benefits

1. Reusable
2. More stable: Less prone to breakdown.
3. No enzyme in product: No need for a separation process.

• Note: Immobilised enzymes are not inherently cheaper; savings are from not separating enzymes from products.

Uses of Immobilised Enzymes

1. Cheese production: Rennin coagulates milk.
2. Sweetening soft drinks: Glucose isomerase converts glucose to fructose, sweetening soft drinks.

Relevant Experiment

• Prepare an enzyme immobilisation and examine application.

Example: Immobilising Lactase

1. Immobilising Lactase:

   • Trap lactase in a gel to prevent mixing with milk.

2. Set-Up:

   • Immobilised lactase in a container; milk is poured over it.

3. Reaction:

   • Lactase breaks down lactose into glucose and galactose.

4. Product Collection:

   • Lactose-free milk is collected, safe for lactose-intolerant individuals.

5. Reuse of Enzyme:

   • Enzyme remains for further use without additional lactase.

Why Useful

• Efficient use as enzyme is not wasted.
• Faster process without repetitive enzyme addition and separation.