Immobilization involves attaching enzymes or cells to insoluble carriers to make them stable and reusable. The main immobilization techniques are adsorption, covalent binding, ionic interactions, cross-linking, and entrapment. Immobilization provides advantages like enabling enzyme use in non-aqueous solvents and extreme pH/temperatures while maintaining activity. It also allows for reuse of enzymes and reduces product inhibition. The document discusses various industrial applications of immobilized enzymes and cells in areas like biomedical treatment, food production, biofuel synthesis, waste treatment, and more.
1. Faculty of science
M.Sc in biotechnology
Enzymes and cells Immobilization and their industrial
applications
presented by
Essam Yahya
2. INTRODUCTION
Enzymes are sensitive, unstable biocatalysts:
needs water to perform
Not ideal catalysts and somewhat undesirable in
most of the synthesis process
Industry needs a stable catalysts.
Immobilization can make the enzyme or the active
cells stable and less sensitive toward environment
What is immobilization?
5. WHY USE IMMOBILIZED ENZYME / CELLS ?
Enable to employment of enzyme:
In different solvent
At extreme of pH and temperature
Exceptionally high substrate concentration
It can also modify the following things at the same
time:
Substrate specifity
Enantioselectivity and
Reactivity
6. PROPERTIES OF THE IDEAL CARRIER REQUIRED FOR ENZYME / CELLS
IMMOBILIZATION
1- Inertness
2- Physical strength.
3- Stability.
4- Cost low and of optimum quality.
5- Regenerability.
6- Reduction in product inhibition.
7- Enhancement of enzyme specificity.
8. (1) ADSORPTION
Physical Adsorption of enzyme protein on the surface of water-insoluble carriers.
Advantages : no reagents and only a minimum of activation steps are required.
Disadvantages : the adsorbed enzyme may leak from the carrier during use due
to a weak binding force between the enzyme and the carrier. Moreover, the
adsorption is non-specific, further adsorption of other proteins or other
substances.
ADVANTAGES DISADVANTAGES
1. Simple and economical 1. Relatively low surface area for binding.
2. Limited loss of activity 2.Exposure of enzyme to microbial attack.
3. Can be Recycled, Regenerated & Reused 3. Yield are often low due to inactivation and
desorption.
9. (2) COVALENT BINDING
Based on the binding of enzymes and water-insoluble carriers by
covalent bonds. The functional groups that may take part in this binding
maybe an Amino group, Carboxyl, Sulfhydryl, Hydroxyl…etc
Advantages : the binding force between enzyme and carrier is so strong
that no leakage of the enzymes occurs, even in the presence of
substrate or solution of high ionic strength.
ADVANTAGES DISADVANTAGES
1. Strong binding, and No leakage of
the enzymes occurs.
1. may alter the conformational structure
and active center of the enzyme
2. even in the presence of substrate
or solution of high ionic strength, no
leakage occurs.
2- major loss of activity and/or changes of
the substrate.
10. (3) IONIC INTERACTIONS
Of the enzyme protein to water-insoluble carriers containing ion-exchange
residues Polysaccharides and synthetic polymers having ion-exchange
centers are usually used as carriers.
Advantages : the enzyme to carrier linkages is much stronger for
ionic binding.
Disadvantages : the binding forces between enzyme proteins and
carriers are weaker than those in covalent binding.
ADVANTAGES DISADVANTAGES
1. the enzyme to carrier linkages is
much stronger for ionic binding.
1. the binding forces between enzyme
proteins and carriers are weaker than those
in covalent binding.
2. Relatively not expensive. 2. Not suitable for many applications.
11. (4) CROSS LINKING
Either to other protein molecules or to functional groups on an insoluble
support matrix.
Advantages : It is used mostly as a means of stabilizing adsorbed
enzymes and also for preventing leakage from polyacrylamide gels
The most common reagent used for cross-linking is glutaraldehyde.
Disadvantages : Cross-linking reactions are carried out under
relatively severe conditions. These harsh conditions can change the
conformation of active center of the enzyme; and so may lead to
ADVANTAGES DISADVANTAGES
1. Very little desorption ( enzyme
strongly bound).
1. Cross linking may cause significant
changes in the active site.
2. Higher stability (i.e.pH, ionic &
substrate concentaration)
2. Not cost effective.
12. (5) ENTRAPMENT
This method differs from the covalent binding and cross linking in
that the enzyme itself does not bind to the gel matrix or membrane.
This results in a wide applicability
Advantages : Loss of enzyme activity upon immobilization is
minimized.
Disadvantages : The enzyme can leak into the surrounding
medium. Another problem is the mass transfer resistance to
substrate and products.
ADVANTAGES DISADVANTAGES
1. No chemical modification. 1. The enzymes may leak from the pores.
2. Relatively stable forms. 2- Substrate can not diffuse deep in to the
gel matrix.
3. Easy handling and reusage. 3- the mass transfer resistance to
substrate and products.
15. INDUSTRIAL APPLICATIONS OF ENZYME AND CELL IMMOBILIZATION
Biomedical applications : diagnosis and treatment of many diseases.
food industry: enzymes like pectinases and cellulases immobilized on
suitable carriers are successfully used in the production of jams ,jellies.
Production of bio-diesel from vegetable oils : Lipase catalyses the
reaction with less energy requirements and mild conditions required
which results in repeated use and stability .
Waste water management: treatment of sewage and industrial
effluents by used immobilized enzymes like preoxidases and laccase.
Textile industry: The immobilization enzymes such as cellulase,
amylase, pectinase are used for various textile applications such as
scouring, biopolishing , denim finishing .
16. Detergent industry: The detergent industry also employs enzymes for
removal of stains. The enzymes used in detergent industry are:
- Protease which is used to remove the stains of blood, egg.
- Amylase used to remove the starch and Lipase used to remove the
stains of oil.
In diary industry the immobilized enzymes are used to coagulate the
milk protein during cheese making and to treat the waste whey.
In pharmaceutical industry, immobilized enzymes are used in enzyme
therapy.
- The asparginase is covalently bound with zinc ions and used in
treatment of leukaemias.
- Zinc ions are used to enhance treatment of diabetes, by increasing the
survivability and reaction potential of the insulin.