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Chromatic and membrane based bioseparation methods, immobilization of enzymes and cells and their application for bioconversion processes.

Chromatic and membrane based bioseparation methods, immobilization of enzymes and cells and their application for bioconversion processes



1. Introduction

Bioseparation techniques are essential steps in downstream processing for the recovery and purification of biomolecules such as enzymes, proteins, antibiotics and metabolites. Among these, chromatographic methods and membrane-based separation techniques are widely used. Immobilization of enzymes and cells further enhances the efficiency, stability and reusability of biocatalysts in bioconversion processes.


2. Chromatographic Bioseparation Methods
2.1 Principle of Chromatography
Chromatography is a separation technique based on the differential distribution of components between a stationary phase and a mobile phase. Components move at different rates depending on their interaction with the stationary phase.
2.2 Types of Chromatographic Methods
a) Ion Exchange Chromatography
Separation based on charge differences of biomolecules
Uses cation and anion exchange resins
Applications:
Purification of proteins and enzymes
Separation of amino acids
b) Gel Filtration (Size Exclusion) Chromatography
Separation based on molecular size
Larger molecules elute first
Applications:
Desalting of protein solutions
Molecular weight determination
c) Affinity Chromatography
Based on specific interaction between ligand and target molecule
Highly selective method
Applications:
Purification of enzymes, antibodies and recombinant proteins
d) Hydrophobic Interaction Chromatography (HIC)
Separation based on hydrophobic interactions
Operates under mild conditions
Applications:
Protein purification without denaturation
2.3 Advantages of Chromatography
High resolution and specificity
Suitable for sensitive biomolecules
High purity product
Limitations
Expensive
Difficult scale-up
Time-consuming
3. Membrane-Based Bioseparation Methods
3.1 Principle
Membrane separation uses semi-permeable membranes that allow selective passage of molecules based on size, charge or pressure gradient.
3.2 Types of Membrane Processes
a) Microfiltration (MF)
Pore size: 0.1–10 µm
Removes cells and debris
b) Ultrafiltration (UF)
Pore size: 1–100 nm
Retains proteins and enzymes
c) Nanofiltration (NF)
Separates small organic molecules and ions
d) Reverse Osmosis (RO)
Separates water from solutes
Requires high pressure
3.3 Applications of Membrane Separation
Cell harvesting
Concentration of enzymes
Desalting of proteins
Wastewater treatment
3.4 Advantages
Low energy consumption
No phase change
Easy scale-up
Limitations
Membrane fouling
Limited selectivity
Membrane replacement cost
4. Immobilization of Enzymes and Cells
4.1 Definition
Immobilization is the physical confinement or localization of enzymes or cells onto or within a support matrix, retaining their catalytic activity and allowing repeated use.
4.2 Methods of Immobilization
a) Adsorption
Enzymes bound to support by weak forces
Simple and cost-effective
b) Covalent Binding
Strong bond between enzyme and support
High stability
c) Entrapment
Enzymes trapped within gel matrix (alginate, polyacrylamide)
d) Encapsulation
Enzymes enclosed within semi-permeable membranes
4.3 Advantages of Immobilization
Reusability of enzymes and cells
Enhanced stability
Easy product separation
Continuous processing
Limitations
Reduced activity due to diffusion limitation
High initial cost
5. Applications of Immobilized Enzymes and Cells in Bioconversion
5.1 Bioconversion Processes
Bioconversion refers to the use of biological systems to convert substrates into valuable products.
5.2 Applications
Glucose isomerase → glucose to fructose (HFCS production)
Immobilized yeast cells → ethanol production
Immobilized lactase → lactose-free milk
Amino acid production
Pharmaceutical and fine chemical synthesis
6. Conclusion
Chromatographic and membrane-based bioseparation techniques play a vital role in downstream processing by ensuring product purity and recovery. Immobilization of enzymes and cells significantly improves the efficiency, stability and economic feasibility of bioconversion processes. Together, these technologies contribute to sustainable and large-scale industrial bioprocessing.



Chromatography is based on
A. Solubility only
B. Boiling point
C. Differential distribution between phases
D. Density
✅ Answer: C
The stationary phase in chromatography is
A. Always liquid
B. Always gas
C. Solid or liquid supported on solid
D. Plasma
✅ Answer: C
The mobile phase in chromatography may be
A. Solid only
B. Liquid or gas
C. Gel only
D. Plasma only
✅ Answer: B
Elution in chromatography refers to
A. Binding of sample
B. Injection of sample
C. Removal of separated components
D. Column packing
✅ Answer: C
Chromatography is mainly used in bioprocessing for
A. Fermentation
B. Purification of biomolecules
C. Sterilization
D. Media preparation
✅ Answer: B
Types of Chromatography
Ion exchange chromatography separates molecules based on
A. Size
B. Shape
C. Charge
D. Density
✅ Answer: C
Anion exchangers carry
A. Positive charge
B. Negative charge
C. Neutral charge
D. No charge
✅ Answer: B
Gel filtration chromatography is also known as
A. Adsorption chromatography
B. Affinity chromatography
C. Size exclusion chromatography
D. Partition chromatography
✅ Answer: C
In gel filtration, which molecules elute first?
A. Small molecules
B. Large molecules
C. Charged molecules
D. Polar molecules
✅ Answer: B
Affinity chromatography is based on
A. Size difference
B. Charge difference
C. Specific ligand–target interaction
D. Solubility
✅ Answer: C
Advanced Chromatography
Hydrophobic interaction chromatography separates proteins based on
A. Size
B. Charge
C. Hydrophobicity
D. Density
✅ Answer: C
Affinity chromatography gives
A. Low purity
B. Very high purity
C. No separation
D. Denatured protein
✅ Answer: B
Chromatographic techniques are preferred because they
A. Are cheap
B. Provide high resolution
C. Need no equipment
D. Are slow
✅ Answer: B
One limitation of chromatography is
A. Low specificity
B. High cost
C. Low purity
D. Poor recovery
✅ Answer: B
HPLC stands for
A. High Power Liquid Chromatography
B. High Performance Liquid Chromatography
C. High Pressure Liquid Column
D. High Purity Liquid Chromatography
✅ Answer: B
Membrane-Based Bioseparation
Membrane separation works mainly on the basis of
A. Color
B. Size and pressure gradient
C. Temperature
D. Density
✅ Answer: B
Microfiltration pore size ranges between
A. 1–100 nm
B. 0.1–10 µm
C. <1 nm
D. >100 µm
✅ Answer: B
Ultrafiltration is commonly used for
A. Cell removal
B. Protein and enzyme concentration
C. Gas separation
D. Sterilization
✅ Answer: B
Reverse osmosis requires
A. Low pressure
B. No pressure
C. High pressure
D. Vacuum
✅ Answer: C
Nanofiltration lies between
A. MF and UF
B. UF and RO
C. MF and RO
D. RO and dialysis
✅ Answer: B
Applications of Membrane Processes
Membrane separation avoids
A. Energy use
B. Phase change
C. Fouling
D. Pressure
✅ Answer: B
One major drawback of membrane processes is
A. High purity
B. Low energy consumption
C. Membrane fouling
D. Easy operation
✅ Answer: C
Membrane processes are preferred because they are
A. Complex
B. Easy to scale up
C. Highly toxic
D. Expensive
✅ Answer: B
Microfiltration is mainly used for
A. Protein purification
B. Cell harvesting
C. Desalting
D. Water purification
✅ Answer: B
Ultrafiltration retains
A. Water only
B. Salts only
C. Proteins and enzymes
D. Gases
✅ Answer: C
Immobilization of Enzymes and Cells
Immobilization refers to
A. Enzyme destruction
B. Physical confinement of enzymes or cells
C. Enzyme denaturation
D. Enzyme dilution
✅ Answer: B
Immobilized enzymes are preferred because they
A. Are unstable
B. Can be reused
C. Have low activity
D. Are toxic
✅ Answer: B
Adsorption immobilization involves
A. Strong covalent bonds
B. Weak physical forces
C. Gel formation
D. Chemical cross-linking
✅ Answer: B
Covalent binding immobilization provides
A. Low stability
B. High stability
C. Easy enzyme leakage
D. Weak attachment
✅ Answer: B
Entrapment involves
A. Binding to surface
B. Trapping enzymes in gel matrix
C. Chemical bonding
D. Free enzymes
✅ Answer: B
Immobilization Methods & Supports
Alginate is commonly used for
A. Adsorption
B. Entrapment
C. Covalent binding
D. Cross-linking
✅ Answer: B
Encapsulation differs from entrapment because
A. No membrane used
B. Semi-permeable membrane is used
C. Strong covalent bonds
D. No diffusion occurs
✅ Answer: B
Immobilized cells are used mainly in
A. Sterilization
B. Continuous bioprocesses
C. Chromatography
D. Microscopy
✅ Answer: B
Major limitation of immobilization is
A. Reusability
B. Stability
C. Diffusion limitation
D. Easy separation
✅ Answer: C
Supports for immobilization should be
A. Toxic
B. Inert and stable
C. Soluble
D. Reactive
✅ Answer: B
Applications in Bioconversion
Bioconversion refers to
A. Chemical synthesis
B. Conversion using biological systems
C. Thermal degradation
D. Mechanical processing
✅ Answer: B
Immobilized glucose isomerase is used in
A. Ethanol production
B. High fructose corn syrup production
C. Antibiotic production
D. Vaccine production
✅ Answer: B
Immobilized yeast cells are used for
A. Cheese making
B. Ethanol production
C. Enzyme purification
D. Bioremediation
✅ Answer: B
Immobilized lactase is used to produce
A. Cheese
B. Yogurt
C. Lactose-free milk
D. Butter
✅ Answer: C
Immobilization allows operation under
A. Extreme conditions only
B. Continuous process conditions
C. Sterile conditions only
D. Solid state only
✅ Answer: B
General & Applied
Chromatography is mainly a
A. Upstream process
B. Downstream process
C. Sterilization method
D. Culture method
✅ Answer: B
Membrane separation is mainly used for
A. Mixing
B. Heating
C. Separation and concentration
D. Aeration
✅ Answer: C
Immobilized enzymes show increased
A. Sensitivity
B. Operational stability
C. Toxicity
D. Leakage
✅ Answer: B
Continuous bioconversion is economically feasible due to
A. Free enzymes
B. Immobilized biocatalysts
C. Chemical catalysts
D. High energy input
✅ Answer: B
Bioseparation methods ensure
A. Contamination
B. Low purity
C. Product recovery and purity
D. Waste formation
✅ Answer: C
Final Questions
Affinity chromatography is most suitable for purifying
A. Sugars
B. Proteins and antibodies
C. Lipids
D. Nucleotides
✅ Answer: B
Membrane fouling reduces
A. Purity
B. Flux rate
C. Pressure
D. Selectivity
✅ Answer: B
Immobilized enzyme reactors commonly use
A. Stirred tanks
B. Packed bed reactors
C. Autoclaves
D. Incubators
✅ Answer: B
Compared to free enzymes, immobilized enzymes show
A. Shorter life
B. Longer operational life
C. Lower stability
D. Less control
✅ Answer: B
The main advantage of bioseparation techniques is
A. Cost increase
B. Process complexity
C. High specificity and efficiency
D. Waste generation
✅ Answer: C



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