Bioprocessing with Immobilised Cells

Bioprocessing with Immobilised Cells

Bioprocessing with immobilised cells involves using cells that have been immobilised to carry out enzyme-controlled reactions for producing useful products.

How Cells Are Immobilised:

• Cells are immobilised in a process similar to how enzymes are immobilised.
• Steps for Immobilising Cells:
  1. Cells (e.g., yeast) are mixed with sodium alginate.
  2. The yeast/alginate mixture is soaked in calcium chloride, which causes the alginate to form beads around the yeast cells.
  3. These beads immobilise the yeast cells while allowing substrates and products to pass through the pores.
• Pores in the Beads:
  • The pores are too small for the yeast cells to pass out.
  • However, the pores are large enough for substrates to enter and products to leave.

Uses of Immobilised Cells in Bioprocessing:

• Immobilised cells are widely used to produce many of the modern bioprocessed products mentioned in earlier notes, such as:
  • Solvents
  • Amino acids
  • Vitamins
  • Drugs
  • Food additives
  • Enzymes
  • Fuels like biogas
  • Flavourings
• Immobilised E. coli is used in water treatment to detoxify sewage in wastewater.

Advantages of Immobilised Cells:

1. Stability:

• The immobilisation process does not harm the cells, and the cells remain very stable.

2. Easy Separation:

• Immobilised cells can be easily separated from the products at the end of the procedure.
• This eliminates the need for difficult and expensive filtration methods to separate products from cells.

3. Reusability:

• Immobilised cells can be reused many times, making the process more cost-effective.