Biotechnology Notes

Biotechnology

Why Use Microorganisms in Biotechnology?

• Advantages of Using Bacteria:
  • Rapid Growth: Bacteria reproduce quickly via binary fission (approximately every 20 minutes).
  • Simple Nutritional Needs: Bacteria can grow using basic nutrients.
  • Easily Genetically Modified: Bacterial DNA is universal and can be altered for useful applications, enabling the production of complex proteins.
  • Large-Scale Production: Bacteria can be cultured in industrial fermenters.
  • Plasmids: Bacteria contain plasmids, which are small, circular DNA molecules that are separate from the bacterial chromosome.

Fermentation

• Definition: Fermentation is the anaerobic respiration of microorganisms to produce useful products.
• Uses of Fermentation:
  • Making Alcohol (Ethanol Production): Yeast respires anaerobically, converting glucose into ethanol, which is used in beverages and biofuels.
    • Conditions: No oxygen, optimal temperature (30-40°C).
  • Biofuel Production: Ethanol from sugar cane or corn is used as a renewable fuel.
    • Advantage: Reduces reliance on fossil fuels.

Enzymes in Biotechnology

• Pectinase (Used in Fruit Juice Production):
  • Breaks down pectin in plant cell walls, increasing juice yield.
  • Used in: Fruit juice industry for clearer juice.
• Lactase (Used in Dairy Industry):
  • Breaks down lactose (milk sugar) into glucose and galactose.
  • Used to make lactose-free milk for lactose-intolerant people.
• Enzymes in Washing Powders:
  • Protease: Breaks down proteins (e.g., blood stains).
  • Lipase: Breaks down oil and grease.
  • Amylase: Breaks down starch stains.
  • Work best at lower temperatures (30-40°C) to save energy and can be used even if there is no access to hot water.

Lactase Beads

• The beads increase surface area for enzyme reactions.
• Provide higher resistance to temperature and pH changes.
• No contamination of milk by lactase enzymes.

Fermenters (Industrial Bioreactors)

• Definition: Large containers for growing microorganisms under controlled conditions.
• Features:
  • Pipes (inlets and outlets) for providing or removing products.
  • Provide oxygen, nutrients, pH, and temperature control.
• Antibiotic Production (Penicillin):
  • Microorganism: Penicillium mold.
  • Process:
    • Penicillium is grown in a fermenter.
    • The fungus produces penicillin after growth.
    • Penicillin is extracted and purified.

Parts of Fermenters

• Cooling Jacket: Maintains optimum temperature by circulating cold water, preventing overheating due to microbial respiration.
• Air Supply (Aeration System): Supplies oxygen for aerobic respiration (important for aerobic fermentation like antibiotic production).
• Nutrient Inlet: Supplies essential nutrients (glucose, amino acids, minerals) for microbial growth.
• Stirrer / Agitator: Mixes nutrients, oxygen, and microorganisms to ensure uniform growth and prevent clumping.
• pH Sensor: Monitors and maintains the correct pH for optimal enzyme activity and microbial growth.
• Temperature Probe: Measures temperature to ensure ideal conditions for microbial activity.
• Pressure Release Valve: Prevents excessive gas buildup inside the fermenter.
• Harvesting Outlet: Extracts the final product (e.g., penicillin, enzymes, or alcohol) from the fermenter.
• Sterile Air Filter: Ensures contamination-free air enters the fermenter, preventing unwanted microbes from interfering.
• Foam Control System: Prevents excessive foam formation using antifoaming agents.

Genetic Engineering

• Definition: The deliberate modification of an organism’s genetic material (DNA) by inserting, deleting, or altering specific genes to produce desired traits.
• Example: Inserting the human insulin gene into bacteria to produce insulin for diabetes treatment.

Enzymes Involved in Genetic Engineering

• Restriction Enzyme: The "scissor" that cuts DNA.
• DNA Ligase: The "glue" that joins DNA fragments.

Steps in Genetic Engineering of Proteins (Insulin)

• A restriction enzyme (also called a restriction endonuclease) is used to cut out the desired gene from an organism’s DNA.
  • The enzyme cuts at specific sequences, creating sticky ends.
• The same restriction enzyme cuts open a plasmid (circular DNA from bacteria), producing complementary sticky ends.
• The desired gene is inserted into the plasmid.
• The enzyme DNA ligase joins the gene into the plasmid, forming recombinant DNA.
• The recombinant plasmid is introduced into bacteria, which multiply and produce the desired protein (e.g., insulin).

Impact or Implications of GMOs

• Pros of GMOs:
  • Higher yield (crop, milk, meat).
  • Disease resistance.
  • Reduced use of pesticides and antibiotics.
  • Improved nutrition.
• Cons of GMOs:
  • Lack of research on side effects.
  • Risk of allergic reactions.
  • GM crops outcompete natural varieties.
  • Ethical and religious concerns about modifying genes.
  • Possible spread of modified genes to wild plants.

Example: Golden Rice

• What is Golden Rice? Genetically modified rice that contains beta-carotene (Vitamin A).
• Why is it Important?
  • Helps prevent Vitamin A deficiency (a major cause of blindness and death in children in developing countries).
  • Aims to improve malnutrition globally.
• Concerns About Golden Rice:
  • Cost of production.
  • Ethical concerns about GMOs.
  • Farmers’ dependence on biotech companies (monopoly by big companies).