Biotechnology and Its Applications

Biotechnology is a broad field of science that uses living organisms, biological systems, or derivatives to develop or modify products and processes for specific purposes. It combines knowledge from biology, chemistry, genetics, and engineering to innovate in areas like healthcare, agriculture, environment, and industry. Modern biotechnology has revolutionized many sectors by enabling the development of genetically modified organisms (GMOs), production of therapeutic drugs, improved agricultural practices, and solutions for environmental sustainability. It plays a critical role in addressing global challenges such as food security, disease control, and climate change.

1.0Biotechnology Applications In Agriculture

Introduction

• Biotechnology, essentially deals with industrial scale production of biopharmaceuticals and biologicals using genetically modified microbes, fungi, plants and animals.

Application of Biotechnology 

• Therapeutics,
• Diagnostics, 
• Genetically modified crops for agriculture, 
• Processed food, 
• Bioremediation, 
• Waste treatment, 
• Energy production

Three critical research areas of biotechnology are

(i) Providing the best catalyst in the form of an improved  organism, usually a microbe or pure enzyme.

(ii) Creating optimal conditions through engineering for a catalyst to act, and

(iii) Downstream processing technologies to purify the protein/organic compound.

The Three Options For Increasing Food Production

• Agro-chemical based agriculture;
• Organic agriculture; and
• Genetically engineered crop-based agriculture.

Green Revolution

• Succeeded in tripling the food supply but yet it was 
• Increased yields have partly been due to the 
• Use of improved crop varieties, better management practices and use of agrochemicals (fertilisers and pesticides). 

Drawbacks : 

• Not enough to feed the growing human population. 
• Agrochemicals are often too expensive, 
• Increases in yield with existing varieties are not possible using conventional breeding.

Plant Tissue Culture

(1) Micro-propagation

• The method of producing thousands of plants through tissue culture in a very short duration is called micro-propagation. 
• A large number of plants can be propagated in very short durations. 
• These plants are called somaclones as they are genetically identical to the original plant from which they were grown.

Example : Commercial scale production of tomato, banana, apple, etc.

(2) Meristem culture

• This method is the recovery of healthy plants from diseased plants. 
• Even if the plant is infected with a virus, the meristem (apical and axillary) is free of virus. 
• One can remove the meristem and grow it in vitro to obtain virus-free plants.
• Meristems culture examples of banana, sugarcane, potato, etc.

(3) Somatic hybridisation

(i) Removal of cell wall : In this step, the cell wall is digested by using pectinase & cellulase enzymes. 

(ii) Fusion between protoplast :-

• Protoplasts of two different species are fused together. 
• Substances which induce the fusion of protoplasts are called fusogens or fusogenic agents. 
• Fusogenic substance or conditions for fusion of protoplast 

(iii) Culture of the fused protoplast :

• The product of fused protoplasts of two different species is called heterokaryon. 
• Heterokaryons are mainly used in tissue culture. 
• When the fused protoplasts are cultured on a suitable medium they regenerate cell walls and begin to divide to ultimately produce plantlets.

Genetic Engineering In Agriculture

1. Genetically Modified Organisms (GMO) : Plants, bacteria, fungi and animals whose genes have been altered by manipulation. 
2. GM plants have been useful in many ways.

(i) Made crops more tolerant to abiotic stresses (cold, drought, salt, heat).

(ii) Reduced reliance on chemical pesticides (pest-resistant crops).

(iii) Helped to reduce post harvest losses.

(iv) Increased efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil).

(v) Enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’ enriched rice.

(vi) To create tailor-made plants to supply alternative resources to industries, in the form of starches, fuels and pharmaceuticals.

Insect Resistant Plant – Bt Technology

• To decrease the amount of pesticide used, the pest resistant plants are produced (bio-pesticide).
• Bt toxin is produced by a bacterium called Bacillus thuringiensis (Bt for short). 
• Bt toxin gene has been cloned from the bacteria and been expressed in plants to provide resistance to insects without the need for insecticides; in effect creating a. 
• Examples are Bt cotton, Bt corn, rice, tomato, potato and soyabean etc. 
• The choice of genes (cry gene) depends upon the crop and the targeted pest, as most Bt toxins are insect-group specific.

B. thuringiensis forms protein crystals (toxic insecticidal protein) during a particular phase of their growth

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The Bt toxin protein exist as inactive protoxins

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Insect ingest the inactive toxin

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Converted into an active form of toxin due to the alkaline pH of the gut 

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The activated toxin binds to the surface of midgut epithelial cells

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Create pores that cause cell swelling and lysis

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eventually cause death of the insect

Pest Resistant Plant – Rna Interference

Principle of RNA interference : 

• RNA takes place in all eukaryotic organisms as a method of cellular defense. 
• This method involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA (silencing).
• The source of this complementary RNA could be from an infection by viruses having RNA genomes or mobile genetic elements (transposons) that replicate via an RNA intermediate. 

Application in Agriculture : 

• A nematode Meloidegyne incognitia infects the roots of tobacco plants and causes a great reduction in yield.

Methodology : 

Nematode-specific genes were introduced into the host plant using Agrobacterium vectors.

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Introduction of DNA which produced both sense and anti-sense RNA in the host cells.

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Two RNAs being complementary to each other formed a double stranded (dsRNA)

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Initiated RNAi

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Silenced the specific mRNA of the nematode 

(prevents translation of mRNA)

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The parasite could not survive in a transgenic host expressing specific interfering RNA.

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The transgenic plant therefore got itself protected from the parasite

Biotechnology Applications In Medicine

At present, about 30 recombinant therapeutics have been approved for human-use the world over. In India, 12 of these are presently being marketed.

Genetically Engineered Insulin

• Insulin used for diabetes extracted from pancreas of slaughtered cattle and pigs. caused allergy or other types of reactions to the foreign protein in patients. 
• Insulin consists of two short polypeptide chains: chain A and chain B, that are linked together by disulphide bridges.
• In mammals, including humans, insulin is synthesised as a pro-hormone which contains an extra stretch called the C peptide. 

• The main challenge for production of insulin using rDNA techniques was getting insulin assembly of insulin into a mature form. 
• In 1983, Eli Lilly, an American company made recombinant insulin.

Two DNA sequences corresponding to A and B, chains of human insulin 

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Introduced them in plasmids of E. coli

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produce insulin chains.

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Chains A and B were produced separately, extracted

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Combined by creating disulfide bonds to form human insulin.

Gene Therapy :

• Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child/embryo.
• Correction of a genetic defect involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-functional gene.
• The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency (due to the deletion of the gene for adenosine deaminase). 
• This enzyme is crucial for the immune system to function. 

Molecular Diagnosis

PCR :

• Very low concentration of a bacteria or virus can be detected by amplification of their nucleic acid.
• Routinely used to detect HIV in suspected AIDS patients. 
• Used to detect mutations in genes in suspected cancer patients too. 
• To identify many other genetic disorders.

Autoradiography :

• Principle : A single stranded DNA or RNA, tagged with a radioactive molecule (probe) is allowed to hybridise to its complementary DNA in a clone of cells followed by detection using autoradiography. 
• The clone having the mutated gene will hence not appear on the photographic film, because the probe will not have complementarity with the mutated gene.

Elisa

• Principle : Antigen-antibody interaction. 
• Infection by pathogen can be detected by the presence of antigens (proteins, glycoproteins, etc.) or by detecting the antibodies synthesised against the pathogen.

Transgenic Animals

• Animals that have had their DNA manipulated to possess and express an extra (foreign) gene. 
• Transgenic rats, rabbits, pigs, sheep, cows and fish have been produced.
• Over although 95 per cent of all existing transgenic animals are mice.

Uses Transgenic Animals : 

Normal physiology and development : 

• The study of how genes are regulated, 
• How they affect the normal functions of the body and its development, e.g., study of complex factors involved in growth such as insulin-like growth factor. 

Study of disease: 

• Transgenic animals serve as models for human diseases so that investigation of new treatments for diseases is made possible. 
• Cancer, 
• Cystic fibrosis, 
• Rheumatoid arthritis and 
• Alzheimer’s.

Biological products: 

• Transgenic animals that produce useful biological products to treat many diseases like emphysema, phenylketonuria (PKU) and Cystic fibrosis. 

Examples : 

• Human protein (α-1-antitrypsin) used to treat emphysema. 
• In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk (2.4 grams per litre – human alpha-lactalbumin). 
• The milk was nutritionally a more balanced product for human babies than natural cow-milk.

Vaccine safety :

• Transgenic mice are being used to test the safety of the polio vaccine as they are found to be reliable.

Chemical toxicity/safety testing: 

• Used for testing toxicity of drugs.
• Transgenic animals are used for testing as
• Carry genes which make them more sensitive to toxic substances than non-transgenic animals. 
• To obtain results in less time.

Ethical Issues

• The Indian Government has set up organisations such as GEAC (Genetic Engineering Approval Committee), 
• It will make decisions regarding the validity of GM research and the safety of introducing GM-organisms for public services. 

Biopiracy : 

• It refers to the use of bio-resources by multinational companies and other organisations without proper authorisation from the countries and people concerned without compensatory payment.
• The Indian Parliament has recently cleared the second amendment of the Indian Patents Bill, that takes such issues into consideration, including patent terms, emergency provisions and research and development initiative.
• Biopiracy attempts have been made for basmati rice and traditional herbal medicines like Neem, Turmeric. 

Biopiracy of Basmati :

• Rice is an important food grain. 
• Basmati rice is distinct for its unique aroma and flavour.
• There are an estimated 200,000 varieties of rice in India alone. 
• 27 documented varieties of Basmati are grown in India. 
• In 1997, an American company got patent rights on Basmati rice through the US Patent and Trademark Office. 
• This ‘new’ variety of Basmati had actually been derived from Indian farmer’s varieties. Indian Basmati was crossed with semi-dwarf varieties and claimed as an invention or a novelty.