Biotechnology and Its Applications

Biotechnology Applications

This chapter Biotechnology and Its Applications, focuses on the diverse applications of biotechnology in agriculture, medicine, and ethical considerations, including advancements like GMOs, gene therapy, and transgenic animals.

Introduction to Biotechnology

Biotechnology deals with the large-scale production of biopharmaceuticals and biologicals, using genetically modified microbes, fungi, plants, and animals. Its applications include:

1. Therapeutics
2. Diagnostics
3. Genetically Modified Crops
4. Processed Food
5. Bioremediation
6. Waste Treatment
7. Energy Production

Critical Research Areas:

• Best Catalyst: Providing improved organisms (usually microbes) or enzymes as catalysts.
• Optimal Conditions: Creating optimal conditions for catalysts to act effectively.
• Downstream Processing: Developing technologies to purify proteins or organic compounds efficiently.

Biotechnological Applications in Agriculture

Green Revolution

• Impact: Tripled food supply but still insufficient for the growing population.
• Methods: Increased yields due to improved crop varieties, management practices, and agrochemicals.
• Challenges: Agrochemicals are expensive and have harmful environmental effects.

Tissue Culture

• Definition: Growing whole plants from explants (plant parts) in test tubes under sterile conditions.
• Totipotency: The ability to regenerate a whole plant from any cell/explant.
• Nutrient Medium Requirements: Must provide carbon source (e.g., sucrose), inorganic salts, vitamins, amino acids, and growth regulators (e.g., auxins, cytokinins).

Micro-Propagation

• Process: Produces thousands of genetically identical plants (somaclones) quickly.
• Commercial Use: Applied to plants like tomato, banana, and apple.

Virus-Free Plants

• Method: Meristem culture (growing virus-free plants from meristem parts of infected plants).
• Success: Effective with banana, sugarcane, potato, etc.

Somatic Hybridisation

• Process: Isolating and fusing protoplasts (cells without cell walls) from different plant varieties to create hybrids.
• Example: Pomato (tomato + potato), though not commercially successful.

Genetically Modified Crops

• Benefits: Potential to increase yields and reduce fertilizer/chemical use.
• Environmental Impact: Minimizes harmful environmental effects.

Options for Increasing Food Production

1. Agro-Chemical Based Agriculture
   • Description: Utilizes synthetic fertilizers and pesticides to enhance crop yield.
   • Advantages:
     • Boosts productivity and efficiency in the short term.
     • Helps control pests and diseases effectively.
   • Disadvantages:
     • High cost of inputs.
     • Contributes to environmental pollution, including soil degradation and water contamination.
2. Organic Agriculture
   • Description: Relies on natural inputs and processes to grow crops.
   • Advantages:
     • Promotes environmental sustainability.
     • Produces healthier food without synthetic chemicals.
   • Disadvantages:
     • Higher production costs.
     • Often results in lower yields compared to conventional methods.
3. Genetically Engineered Crop-Based Agriculture
   • Description: Uses genetically modified organisms (GMOs), which have been altered through genetic manipulation to enhance desired traits.

Genetically Modified Organisms (GMOs)

What are GMOs?

• GMOs are plants, bacteria, fungi, and animals whose genes have been altered by humans.

Benefits of GM Plants

1. Tolerance to Abiotic Stresses
   • Crops can withstand cold, drought, salt, and heat.
2. Reduced Chemical Pesticides
   • Pest-resistant crops reduce the need for pesticides.
3. Reduced Post-Harvest Losses
4. Efficient Mineral Usage
   • Prevents early soil fertility exhaustion.
5. Enhanced Nutritional Value
   • Example: Golden rice enriched with Vitamin A.

Industrial Uses

• GM plants are used to produce starches, fuels, and pharmaceuticals.

Pest Resistant Plants (bio-pesticide)

• Production of pest-resistant plants reduces pesticide use.
• Bt toxin from Bacillus thuringiensis:
  • Description: Bt produces proteins that kill specific insects.
  • Examples: Bt cotton, Bt corn, rice, tomato, potato, and soybean.

Bt Cotton

• Bacillus thuringiensis (Bt): Produces proteins that kill specific insects like tobacco budworm & armyworm (lepidopterans), beetles (coleopterans), flies, and mosquitoes (dipterans).
• Protein Crystals: Bt forms protein crystals during growth phases. These crystals contain an insecticidal protein (Bt Toxin).
• Inactive Protoxins: The Bt toxin protein is inactive (protoxin) in the bacteria. When ingested by insects, it becomes active in the alkaline pH of the insect’s gut.
• Mode of Action:
  • Toxin binds to midgut epithelial cells.
  • Creates pores causing cell swelling, lysis, and death of the insect.
• Bt Gene Incorporation: Specific Bt toxin genes (e.g., cryIAc) are isolated from Bt and incorporated into crops like cotton.
• Gene Choice: Bt toxins, coded by cry genes, are typically specific to certain insect groups. Gene choice depends on the crop and targeted pest.
  • For example, Specific Bt toxin genes (e.g., cryIAc, cryIIAb) are used in crops.
  • cryIAc and cryIIAb genes control cotton bollworms,
  • cryIAb controls corn borer.

Nematode resistance in tobacco plants:

• Nematode Infestation: Nematodes like Meloidegyne incognitia infect plant roots (e.g., tobacco) and reduce yield.
  • This can be prevented using the RNA interference (RNAi) strategy.
• RNA Interference (RNAi):
  • A natural cellular defense in eukaryotes.
  • RNAi silences specific mRNA using complementary dsRNA, preventing translation.
• Source of Complementary RNA: From viruses or mobile genetic elements (transposons).
• Gene Introduction:
  • Nematode-specific genes are introduced into host plants using Agrobacterium vectors.
  • Introduced DNA produces sense and anti-sense RNA, forming dsRNA (double-stranded).
  • dsRNA triggers RNAi, silencing nematode-specific mRNA.
• Effect: Parasite cannot survive in transgenic plants expressing interfering RNA, protecting the plant from the nematode.

Key Takeaways

• GMOs have many benefits in agriculture, including pest resistance, reduced pesticide use, and improved nutrition.
• Bt toxin and RNAi are two key biotechnological methods used to create pest-resistant plants.

Biotechnological Applications in Medicine

Recombinant DNA Technology in Healthcare

• Enables mass production of safe and effective drugs.
• Avoids unwanted immunological responses, even from non-human sources.
• About 30 recombinant therapeutics approved worldwide; 12 available in India.

Genetically Engineered Insulin (Humulin)

• Diabetes Management:
  • Insulin is crucial for managing adult-onset diabetes.
  • Previously sourced from the pancreas of slaughtered cattle and pigs, sometimes causing allergic reactions in humans.
• Insulin Structure:
  • Insulin has two short polypeptide chains: A and B, linked by disulfide bridges.
  • In humans, insulin is produced as a pro-hormone (pro-insulin) with an extra stretch called the C peptide, which is removed to form mature insulin.
• Recombinant Insulin Production:
  • The challenge was to produce mature insulin using rDNA technology.
  • In 1983, Eli Lilly, an American company, created DNA sequences for the A and B chains of human insulin.
  • These sequences were introduced into plasmids of E. coli bacteria to produce the insulin chains separately.
  • The A and B chains were extracted, and combined to form human insulin (Humulin).

By using genetically engineered bacteria, we can now produce large quantities of human insulin, making diabetes management easier and more effective.

Gene Therapy

• What is Gene Therapy?
  • A method to correct genetic defects diagnosed in a child or embryo.
  • Involves inserting normal genes into a person’s cells to treat a disease.
  • Thus, compensating for the non-functional gene.
• First Clinical Gene Therapy:
  • Given in 1990 to a 4-year-old girl with ADA (adenosine deaminase) deficiency, a critical enzyme for the immune system.
  • ADA deficiency caused due to the deletion/fault of a gene of adenosine deaminase.
  • ADA deficiency can sometimes be treated with bone marrow transplantation or enzyme replacement therapy (injection of ADA), but not fully curative.
  • Gene therapy steps:
    1. Lymphocytes from patient’s blood grown in culture (in-vivo).
    2. Functional ADA cDNA introduced using retroviral vector.
    3. Genetically engineered/modified lymphocytes returned to patient.
    4. Periodic infusions needed as the modified cells are not immortal.
  • But early embryonic gene introduction could be permanent cure.

Molecular Diagnosis

• Importance of Early Diagnosis:
  • Early diagnosis and understanding of a disease are crucial for effective treatment.
  • Traditional methods (serum and urine analysis) are not always effective for early detection.
• Advanced Techniques:
  1. PCR (Polymerase Chain Reaction):
     • Amplifies the nucleic acid of pathogens, allowing detection at very low concentrations before symptoms appear.
     • Used to detect HIV and cancer mutations.
  2. ELISA (Enzyme Linked Immuno-sorbent Assay):
     • Based on antigen-antibody interaction.
     • Detects infection by identifying antigens or antibodies against the pathogen.
• Additional Methods:
  • 3. Using radioactive probes to identify mutations:
    • A single-stranded DNA or RNA probe hybridizes to its complementary DNA in cells.
    • Detection is done using autoradiography; mutated genes do not show up on the film.
  • Detailed Mechanism:
    • A single-stranded DNA or RNA probe tagged with a radioactive molecule is used.
    • The probe is hybridized to its complementary DNA in a clone of cells.
    • Detection is performed using autoradiography.
    • Clones with a mutated gene will not appear on the photographic film.
    • This absence occurs because the probe does not bind to the mutated gene due to the lack of complementarity.

Key Takeaways

• Biotechnology has revolutionized medicine with safe drug production and innovative treatments.
• Insulin and gene therapy are major breakthroughs for diabetes and hereditary diseases.
• Molecular diagnosis techniques like PCR and ELISA allow early and accurate detection of diseases.

Transgenic Animals

What are Transgenic Animals?

• Definition: Animals with DNA manipulated to include and express an extra (foreign) gene.
• Common Types: Rats, rabbits, pigs, sheep, cows, fish, and especially mice (over 95% of transgenic animals).

Here are some reasons why transgenic animals are produced and how they benefit us:

Why Create Transgenic Animals?

1. Normal Physiology and Development

• Purpose: To study how genes regulate normal body functions and development.
• Example: Introducing genes from other species to study the effects of insulin-like growth factor.

2. Study of Disease

• Purpose: To understand how genes contribute to diseases.
• Examples: Creating models for human diseases like cancer, cystic fibrosis, rheumatoid arthritis, and Alzheimer’s.

3. Biological Products

• Purpose: To produce medicines that are expensive to make.
• Example: Transgenic animals can produce human proteins like α-1-antitrypsin for treating emphysema.
• Notable Case: In 1997, a transgenic cow named Rosie produced milk enriched with human protein (α-lactalbumin) (2.4 grams per liter),which is more balanced for human babies.

4. Vaccine Safety

• Purpose: To test the safety of vaccines before human use.
• Example: Transgenic mice are used to test the safety of the polio vaccine, potentially replacing monkeys in vaccine testing.

5. Chemical Safety Testing (Toxicity Testing)

• Purpose: To test the toxicity of chemicals and drugs more efficiently.
• Method: Transgenic animals are made more sensitive to toxic substances to study their effects quickly.

Key Takeaways

• Transgenic animals help in genetics, medical research, disease understanding, and product development.
• They provide safer, more effective methods for testing and producing treatments.

Ethical Issues in Biotechnology

Biotechnology has made great strides, but it also brings up important ethical issues. Here’s a breakdown of the main aspects:

Need for Regulation

• Why Regulation needed?
  • Manipulating living organisms without regulation can have unpredictable consequences.
  • Ethical standards ensure human activities don’t harm living organisms.
• Who regulates?
  • In India, the Genetic Engineering Approval Committee (GEAC) regulates GM research and public safety.
  • Ensures safety before GM organisms are used for public services.

Patents and Biopiracy

• Patents Problems:
  • Companies patenting genetic materials and plants traditionally used by farmers and indigenous people.
• Example:
  • In 1997, a US company patented a new variety of Basmati rice derived from Indian varieties.
  • Other examples include herbal medicines like turmeric and neem.
• Biopiracy:
  • Definition: Exploitation of bio-resources by multinational companies and other organizations without proper authorization or compensation from the countries and people concerned.
• Examples:
  • Companies have patented products and technologies using genetic materials and plants identified, developed, and used by indigenous farmers.
  • Notable examples include Basmati rice and herbal medicines like turmeric and neem.
• Case Study – Basmati Rice:
  • Basmati rice is known for its unique aroma and flavor, with India having 27 varieties.
  • In 1997, an American company obtained patent rights on Basmati rice through the US Patent and Trademark Office, allowing them to sell a ‘new’ variety derived from Indian farmer’s varieties.
  • The patent restricted other sellers of Basmati rice.
• Biodiversity and Traditional Knowledge:
  • Disparity:
    • Industrialized nations generally lack biodiversity and traditional knowledge.
    • Developing and underdeveloped countries are rich in both biodiversity and traditional knowledge related to bio-resources.
  • Impact: Developing countries are rich in biodiversity, while developed countries are rich financially but often exploit these resources without fair compensation.
• Legal Measures:
  • Need for Laws:
    • To prevent unauthorized exploitation of bio-resources and traditional knowledge.
  • Actions Taken:
    • Countries are creating laws to prevent unauthorized exploitation.
    • The Indian Parliament has cleared the second amendment of the Indian Patents Bill, addressing patent terms, emergency provisions, and research and development initiatives.
    • These measures aim to ensure fair use of genetic resources and protect the interests of countries rich in biodiversity.

Key Takeaways

• Ethical standards and regulations are crucial in biotechnology.
• Protecting biodiversity and traditional knowledge is important.
• Legal measures help prevent biopiracy and ensure fair use of bio-resources.

Chapter Summary:

• Biotechnology has given humans many useful products.
• It uses microbes, plants, animals, and their metabolic machinery.
• Recombinant DNA technology helps engineer these organisms.
• Genetically Modified Organisms (GMOs) are created using these techniques.
• GM plants help increase crop yields and reduce post-harvest losses.
• They make crops more tolerant to stress and reduce the need for chemical pesticides.
• GM crops have improved nutritional value.
• Recombinant DNA technology has a big impact on healthcare.
• It enables mass production of safe and effective therapeutics.
• Recombinant therapeutics are identical to human proteins.
• They do not cause unwanted immune responses or infections.
• Human insulin made in bacteria is identical to natural insulin.
• Transgenic animals help understand how genes contribute to diseases.
• They serve as models for diseases like cancer, cystic fibrosis, rheumatoid arthritis, and Alzheimer’s.
• Gene therapy inserts genes into cells to treat diseases, especially hereditary ones.
• It replaces defective genes with functional ones.
• Viruses are used as vectors to transfer healthy genes.
• Manipulating microbes, plants, and animals raises serious ethical questions.