Microbial production, purification and bioprocess applications of industrial enzymes and organic compounds.
Microbial Production, Purification and Bioprocess Applications of Industrial Enzymes and Organic Compounds
1. Introduction
Industrial microbiology uses microorganisms such as bacteria, fungi and yeast to produce enzymes and organic compounds of commercial value. These products are widely applied in food, pharmaceuticals, agriculture, textiles, detergents and environmental biotechnology. Microbial processes are preferred because they are cost-effective, scalable, eco-friendly and highly specific.
2. Microbial Production of Industrial Enzymes
Definition of Industrial Enzymes
Industrial enzymes are biological catalysts produced by microorganisms and used to accelerate biochemical reactions under controlled conditions.
Microorganisms Used
Bacteria – Bacillus, Escherichia
Fungi – Aspergillus, Penicillium
Yeast – Saccharomyces
Types of Industrial Enzymes
Amylases
Proteases
Lipases
Cellulases
Pectinases
Lactase
Steps in Enzyme Production
Selection of high-yielding strain
Inoculum preparation
Fermentation process
Submerged fermentation
Solid state fermentation
Optimization of conditions
pH, temperature, aeration, agitation
Harvesting of enzyme
Enzymes may be extracellular or intracellular, which determines the recovery method.
3. Microbial Production of Organic Compounds
Definition
Organic compounds are carbon-containing metabolites produced by microorganisms through fermentation.
Types of Organic Compounds
Alcohols
Organic acids
Amino acids
Vitamins
Solvents
Production Process
Selection of suitable microbial strain
Preparation of nutrient medium
Fermentation under controlled conditions
Accumulation of product in broth or cells
Examples
Ethanol by yeast
Citric acid by fungi
Lactic acid by bacteria
Amino acids by bacteria
4. Purification of Industrial Enzymes
Purification is part of downstream processing, aimed at obtaining enzymes in active and stable form.
Steps in Enzyme Purification
Removal of microbial cells
Filtration or centrifugation
Cell disruption (for intracellular enzymes)
Mechanical or chemical methods
Precipitation
Ammonium sulfate precipitation
Dialysis
Chromatographic techniques
Ion exchange
Gel filtration
Concentration and formulation
5. Purification of Organic Compounds
Recovery Methods
Filtration and centrifugation
Solvent extraction
Distillation
Crystallization
Adsorption
Factors Affecting Purification
Solubility of product
Stability of compound
Presence of impurities
6. Bioprocess Applications of Industrial Enzymes
Food Industry
Amylases in starch processing
Proteases in baking and brewing
Lactase in lactose-free milk
Detergent Industry
Proteases, lipases and amylases for stain removal
Textile Industry
Cellulases for fabric softening
Amylases for desizing
Pharmaceutical Industry
Enzymes in drug synthesis
Diagnostic enzymes
Environmental Applications
Enzymes in waste treatment
Biodegradation of pollutants
7. Bioprocess Applications of Organic Compounds
Food and Beverage Industry
Organic acids as preservatives
Alcohols in fermentation industries
Pharmaceutical Industry
Amino acids and vitamins as supplements
Organic solvents in drug production
Agriculture
Organic acids in soil conditioning
Amino acids as plant growth promoters
Industrial Applications
Solvents and intermediates in chemical industries
8. Advantages of Microbial Production
Rapid growth of microorganisms
High product yield
Use of cheap raw materials
Environment friendly processes
Easy genetic manipulation
9. Limitations
Contamination risk
Cost of downstream processing
Product inhibition
10. Conclusion
Microbial production of industrial enzymes and organic compounds plays a vital role in modern biotechnology. Advances in strain improvement, fermentation technology and purification techniques have greatly enhanced productivity, making microbial bioprocesses indispensable for industrial applications.
MCQs
Microbial Production of Enzymes
Industrial enzymes are mainly produced using
A. Plants
B. Animals
C. Microorganisms
D. Algae
✅ Answer: C
Which microorganism is commonly used for amylase production?
A. Escherichia coli
B. Aspergillus niger
C. Lactobacillus
D. Rhizobium
✅ Answer: B
Submerged fermentation is characterized by
A. Solid medium
B. Liquid nutrient medium
C. No aeration
D. Low moisture
✅ Answer: B
Solid-state fermentation is widely used for the production of
A. Antibiotics
B. Fungal enzymes
C. Vaccines
D. Hormones
✅ Answer: B
Which enzyme is used in detergent industry?
A. Lipase
B. Protease
C. Amylase
D. All of the above
✅ Answer: D
Fermentation & Bioprocess Parameters
The optimum pH for most bacterial enzymes is
A. 2–3
B. 6–7
C. 9–10
D. 11–12
✅ Answer: B
Oxygen transfer in bioreactors is enhanced by
A. Increasing viscosity
B. Decreasing agitation
C. Increasing aeration and agitation
D. Lower temperature
✅ Answer: C
Fed-batch fermentation is preferred to
A. Avoid contamination
B. Prevent substrate inhibition
C. Reduce aeration
D. Stop growth
✅ Answer: B
Which parameter directly affects enzyme yield?
A. Temperature
B. pH
C. Nutrient concentration
D. All of the above
✅ Answer: D
Sterilization of fermenters is commonly done by
A. UV rays
B. Chemicals
C. Steam under pressure
D. Filtration
✅ Answer: C
Purification of Industrial Enzymes
First step in downstream processing is
A. Chromatography
B. Cell separation
C. Drying
D. Crystallization
✅ Answer: B
Centrifugation is mainly used for
A. Enzyme activation
B. Removal of cells
C. Protein folding
D. Enzyme synthesis
✅ Answer: B
Ammonium sulfate precipitation is based on
A. pH difference
B. Charge difference
C. Solubility of proteins
D. Molecular weight
✅ Answer: C
Dialysis is used to remove
A. Proteins
B. Enzymes
C. Small molecules and salts
D. Cells
✅ Answer: C
Chromatography separates biomolecules based on
A. Size
B. Charge
C. Affinity
D. All of the above
✅ Answer: D
Types of Chromatography
Ion-exchange chromatography separates proteins based on
A. Size
B. Charge
C. Shape
D. Density
✅ Answer: B
Gel filtration chromatography is also called
A. Affinity chromatography
B. Adsorption chromatography
C. Size exclusion chromatography
D. Partition chromatography
✅ Answer: C
Affinity chromatography depends on
A. pH
B. Size
C. Specific ligand binding
D. Temperature
✅ Answer: C
HPLC is mainly used for
A. Crude extract separation
B. High-resolution purification
C. Fermentation
D. Sterilization
✅ Answer: B
Elution refers to
A. Binding of enzyme
B. Washing of column
C. Removal of bound molecules
D. Packing of column
✅ Answer: C
Industrial Enzymes & Applications
Proteases are widely used in
A. Food industry
B. Detergent industry
C. Leather industry
D. All of the above
✅ Answer: D
Lipases are used in
A. Baking
B. Biodiesel production
C. Antibiotic synthesis
D. Vaccine production
✅ Answer: B
Cellulases are important in
A. Textile industry
B. Paper industry
C. Biofuel production
D. All of the above
✅ Answer: D
Lactase is used in
A. Bread making
B. Cheese ripening
C. Lactose-free milk production
D. Alcohol production
✅ Answer: C
Pectinase is mainly used in
A. Brewing
B. Fruit juice clarification
C. Cheese production
D. Baking
✅ Answer: B
Microbial Production of Organic Compounds
Citric acid is industrially produced by
A. Saccharomyces cerevisiae
B. Aspergillus niger
C. Penicillium chrysogenum
D. E. coli
✅ Answer: B
Lactic acid is produced by
A. Yeast
B. Algae
C. Lactobacillus
D. Actinomycetes
✅ Answer: C
Ethanol production uses
A. Rhizobium
B. Saccharomyces cerevisiae
C. Bacillus
D. Clostridium
✅ Answer: B
Acetic acid bacteria belong to genus
A. Lactobacillus
B. Bacillus
C. Acetobacter
D. Streptomyces
✅ Answer: C
Butanol is produced by
A. Yeast
B. Clostridium
C. Aspergillus
D. Rhizobium
✅ Answer: B
Bioprocess Applications
Immobilized enzymes are preferred because they
A. Are unstable
B. Can be reused
C. Are expensive
D. Have low activity
✅ Answer: B
Biocatalysts are used in industry due to
A. High specificity
B. Mild reaction conditions
C. Eco-friendliness
D. All of the above
✅ Answer: D
Microbial enzymes help reduce
A. Product yield
B. Reaction rate
C. Environmental pollution
D. Specificity
✅ Answer: C
Enzyme immobilization techniques include
A. Adsorption
B. Entrapment
C. Covalent bonding
D. All of the above
✅ Answer: D
Bioprocess technology mainly aims at
A. Chemical synthesis
B. Large-scale production of biomolecules
C. Waste generation
D. Pollution
✅ Answer: B
General Concepts
Primary metabolites are produced during
A. Death phase
B. Stationary phase
C. Log phase
D. Decline phase
✅ Answer: C
Secondary metabolites are produced during
A. Lag phase
B. Log phase
C. Stationary phase
D. Death phase
✅ Answer: C
Industrial enzymes are preferred over chemical catalysts because they
A. Are toxic
B. Need high temperature
C. Are highly specific
D. Produce waste
✅ Answer: C
GRAS microorganisms means
A. Genetically Resistant
B. Generally Regarded As Safe
C. Growth Resistant
D. Gene Regulated
✅ Answer: B
Which enzyme is used in cheese making?
A. Amylase
B. Protease
C. Rennin
D. Lipase
✅ Answer: C
Advanced & Applied
Downstream processing cost accounts for about
A. 10%
B. 20%
C. 50–60%
D. 5%
✅ Answer: C
Enzyme activity is measured in
A. Gram
B. Mole
C. Units
D. Liter
✅ Answer: C
Microbial bioprocesses are preferred because they are
A. Costly
B. Energy intensive
C. Sustainable
D. Polluting
✅ Answer: C
Which enzyme is used in starch liquefaction?
A. β-amylase
B. α-amylase
C. Cellulase
D. Invertase
✅ Answer: B
Invertase converts
A. Starch to glucose
B. Lactose to glucose
C. Sucrose to glucose and fructose
D. Cellulose to glucose
✅ Answer: C
Final Questions
Industrial microbiology mainly deals with
A. Medical microbes
B. Agricultural microbes
C. Commercial exploitation of microbes
D. Pathogens
✅ Answer: C
Enzyme denaturation leads to
A. Increased activity
B. Loss of biological activity
C. Better stability
D. Reusability
✅ Answer: B
Which factor does NOT affect enzyme activity?
A. Temperature
B. pH
C. Substrate concentration
D. Colour of enzyme
✅ Answer: D
Immobilized enzymes show
A. Lower stability
B. Higher stability
C. No reuse
D. Low specificity
✅ Answer: B
Bioprocess applications contribute to
A. Green technology
B. Sustainable development
C. Industrial growth
D. All of the above
✅ Answer: D
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