Basics of BiotechnologyBy Dr. Roman Saini

Bioinformatics, Genomics, Proteomics, Transcriptomics

Bioinformatics:

● Bioinformatics is the interdisciplinary field that develops relies on computational methods and software tools for understanding and analysis of biological data.

● The field spans across the sciences of computers, biology, chemistry physics, mathematics and engineering and statistics.

Genomics:

● Genomics is the field of study under molecular biology.

● Genomics deals with the study and analyses of the genome i.e. the entire genetic makeup of the organism.

Proteomics:

It is the interdisciplinary study revolving around the proteome i.e. the entire set of proteins that are produced or modified by an organism or system.

Transcriptomics:

Transcriptomics is the study of the transcriptome—the complete set of RNA transcripts that are produced by the genome.

What is Biotechnology?

● Biotechnology deals with techniques of using live organisms or enzymes from organisms to produce products and processes useful to humans.

● This term is used in a restricted sense today, to refer to such of those processes which use genetically modified organisms.

● Many other processes/techniques are also included under biotechnology. E.g.

○ In vitro fertilisation leading to a ‘test-tube’ baby,

○ Synthesising a gene and using it,

○ Developing a DNA vaccine or correcting a defective gene

Techniques Used in Biotechnology

Genetic Engineering

● Genetic Engineering involves the manipulation of the genetic makeup of any organism.

● It is either done through recombinant DNA (r-DNA) or by artificial synthesis of DNA (also called DNA printing at times).

Recombinant DNA (r-DNA) Technology

● Recombinant DNA technology forms the foundation for genetic engineering.

● Using such technology bacteria in the past were engineered to produce human insulin, a hormone which fights diabetes.

● Yeast cells were made to produce Hepatitis B vaccine.

● Plants such as cotton were made insect resistant (Bt-cotton) and so on.

Basic Steps of r-DNA Technology:

● Selecting and isolating enzymatically the target DNA insert or the segment that has to be cloned.

● Restriction Endonuclease - site specific cut

● Selecting a suitable cloning vector into which the DNA segment is integrated.

● The vectors contain a self-replicating DNA molecule that leads to the formation of a large number of copies of cloned DNA in a shorter duration.

● Commonly used vectors are bacterial plasmids and bacteriophages.

● The cloning vectors have specific markers present on their DNA.

● These markers are helpful in distinguishing transformed cells in the later steps.

● The target DNA insert from step 1 is joined to vector DNA by the enzyme ligase. This forms r-DNA molecule which is often called as cloning vector-insert DNA construct.

● The cloning vector-insert DNA construct is inserted in a suitable bacterial host whose cells are prepared to take up a foreign DNA. This process is called transformation.

● Bacterial cells, especially those of E. coli, are the commonly used hosts.

● At times, instead of bacterial cells, microinjection is used to introduce foreign DNA into cells like eggs, zygote or even in embryos.

● In microinjection, the DNA is injected directly into the nucleus of the cell. This is done through a glass micropipette.

● Another method to introduce the DNA into the host cell is gene gun or biolistic particle delivery system.

● In this system, the host cells are bombarded with high velocity microprojectiles, such as particles of gold or tungsten coated with DNA insert.

● The transformation through microinjection or gene gun comes under non-bacterial transformation.

● Sometimes, instead of transformation, the process of transfection is used.

● In transfection, the vector is a phage i.e. a bacteriophage- virus that infects bacteria.

● Selecting the transformed cells from the non-transformed cells.

● Not all host cells get transformed.

● The cells that contain the r-DNA are distinguished from the non-transformed cells by a marker.

● The last step is an expression of the desired traits by the r-DNA.

● Also, multiplication of host cells needs to be done to ensure sufficient copies of r-DNA are created.

Applications of r-DNA Technology

● Production of Genetically Modified Organisms (GMO)- GMO refers to both transgenic or GM crops and transgenic or GM animals that have been modified to express desired traits.

● Production of therapeutic mammalian proteins and hormones. E.g. Human insulin, Growth hormone etc.

● Recombinant DNA vaccines that are based on the expression of biological constructs encoding proteins from specific viral pathogens. E.g. Hepatitis B vaccine is produced with recombinant DNA technology.

● Gene Therapy to correct genetic diseases.

● Production of interferons, which are proteins involved in providing protection against several pathogens, such as viruses, bacteria, parasites, and also tumor cells.

● Efficient production of bioenergy and biofuels through genetically engineered microorganisms.

● Enzyme engineering or protein engineering involves recombinant DNA mutation. Due to this, the sequence of amino acids coded by the gene changes.

● Genetically engineered organisms for bioremediation.

● Asexual reproduction preserves the genetic information, while sexual reproduction permits variation.

● Traditional hybridisation procedures used in plant and animal breeding, very often lead to inclusion and multiplication of undesirable genes along with the desired genes.

● The techniques of genetic engineering which include the creation of recombinant DNA, use of gene cloning and gene transfer, overcome this limitation.

● It also allows us to isolate and introduce only one or a set of desirable genes without introducing undesirable genes into the target organism.

Mitochondrial Replacement Therapy (MRT)● Mitochondrial DNA or mtDNA is maternally inherited, mutations in

mt-DNA are linked to severe genetic diseases in humans.

● MRT is in vitro fertilization technique that uses mitochondrial DNA from a healthy donor to attempt to prevent the transmission of mitochondrial disease from mother to the child.

● Two most common techniques are Spindle Transfer and Pronuclear Transfer.

● Third Technique- Polar Body Transfer for which research is underway.

● In December 2016, the United Kingdom became the first country in the world to formally approve MRT.

Somatic Cell Nuclear Transfer (SCNT)

● Somatic cell nuclear transfer (SCNT) is a laboratory technique for creating an ovum with a donor nucleus.

● SCNT is used in embryonic stem cell research, or in regenerative medicine where it is sometimes referred to as "therapeutic cloning."

● It is the first step towards reproductive cloning.

● The first ever successful clone developed through SNCT was Dolly the sheep.

How it works?

● The nucleus from a somatic cell which contains the organism's DNA is isolated and the rest of the cell discarded.

● Simultaneously, the nucleus of an egg cell is removed. This is called enucleation.

● The nucleus of the somatic cell is then inserted into the enucleated egg cell.

● The somatic cell nucleus is reprogrammed by the host cell after getting inserted into it.

● The egg cell with the somatic cell nucleus is stimulated to divide mitotically.

● After a certain number of mitosis divisions, blastocyst of the embryo is formed which is genetically identical to the original parent.

Artificial Embryo Twinning

● It is another method to produce clones.

● Artificial twinning follows the same process observed in nature which leads to the development of twins.

● In artificial embryo twinning, the process takes place in a lab instead of mother’s womb.

How it works:

● A very early embryo after fertilization is separated into individual cells.

● These cells are allowed to divide and develop for a short time in the Petri dish.

● The embryos are then placed into a surrogate mother where they develop fully.

● The organisms formed are genetically identical as their source is a single fertilized egg.

Vectors

● Vectors such as a plasmid are the vehicles of cloning.

● They serve as a vehicle to carry a foreign DNA sequence into a host cell.

● Features of vectors:

○ It must be independently able to replicate within the host.

○ It should incorporate a selectable marker, a gene whose product can identify the host cells containing the vector.

○ Another desirable feature of a cloning vector is that it should be small in size thereby facilitating entry/transfer into a host cell.

Vector- Plasmids

● Plasmids are extrachromosomal, self-replicating, usually circular, double-stranded DNA molecules found naturally in many bacteria and also in some yeasts.

● Although plasmids are not essential for normal cell growth and division, they often confer useful properties to the host such as resistance to antibiotics that can be a selective advantage under certain conditions.

Vector- Restriction Enzymes

● Restriction enzyme is a protein produced by bacteria that cleaves DNA at specific sites along the molecule. Therefore they are also called molecular scissors.

● In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms.

● Restriction enzymes can be isolated from bacterial cells and used in the laboratory to manipulate fragments of DNA, such as those that contain genes.

● For this reason, they are indispensable tools of recombinant DNA technology (genetic engineering)

● The cutting of DNA by restriction enzymes results in the fragments of DNA and it can be separated by a technique known as gel electrophoresis.

Polymerase Chain Reaction (PCR)

● The polymerase chain reaction or PCR causes selective amplification of a specific region of a DNA molecule.

● And it can also be used to generate a DNA fragment for cloning.

Basic Principle:

● When a double-stranded DNA molecule is heated to a high temperature, the two DNA strands separate giving rise to single stranded molecules which can be made to hybridise with small single-stranded molecules by bringing down the temperature.

Applications:

● To detect pathogens, microbiologists in the past used techniques which were very slow.

● PCR based diagnosis is faster and does not use live pathogens; instead DNA from the infected tissue is isolated and the PCR technique is carried out.

● PCR is also a valuable tool in forensic science as large amounts of DNA can be amplified from the small amounts present at the crime site, for DNA fingerprinting analysis.

● In recent years, PCR has also found use in detecting specific microorganisms from environmental samples of soil, sediments and water.

● Archaeologists are using combinations of PCR and fingerprinting analysis to relate and establish ancient Egyptian dynasties from samples obtained from mummies.

Cell Culture

What is Cell Culture?

● Cell culture refers to the process by which cells, either prokaryotic or eukaryotic are grown in vitro.

● A microbial culture works as a factory in which the metabolism of a microorganism is exploited to convert raw material into products.

● The cells are isolated from the organism and then cultured in an artificial environment under controlled conditions.

● The artificial medium in which the cells grow is called culture medium.

● Like any other chemical reaction, which requires an appropriate temperature, pressure, pH and solvent, microbes also grow in an appropriate environment of pH, temperature, nutrients (provided by the growth medium) and the substrate (raw material), which is converted by the bacterium into the desired product

● The cells can be grown on a semi-solid substrate on which the cells adhere- this is called monolayer culture.

● Sometimes the cells were grown in a suspension culture.

● Cell culture forms the basis for tissue culture and tissue engineering.

● Whatever be the cell type, some general factors are necessary for the growth of the cell.

Any culture medium invariably consists of a suitable vessel that contains the following:

● A substrate or medium that supplies the essential nutrients for growth and development- amino acids, carbohydrates, vitamins and minerals.

● Growth factors

● Hormones

● Gases (O2, CO2)

● Physico-chemical environment that needs to be regulated. This comprises of optimum pH conditions, osmotic pressure and temperature.

● Apart from the factors, the aseptic technique needs to be adopted for cell culture.

● Aseptic culture ensures that the cells do not get damaged upon entry of pathogens or toxins from the external environment.

● Sources of biocontamination include non-sterile supplies, medium and airborne particles containing microorganisms, unclean incubators, and dirty or contaminated work surfaces.

Applications of Cell Culture● The most ancient use of microbial cultures is for the production of fermented

foods such as curd and cheese where the whole bacteria are used as starter cultures.

● The whole microorganisms are also used for preparations such as bacterial vaccines, e.g. vaccines for typhoid and tuberculosis.

● Single cell protein (SCP) is another example where the whole microorganisms are used as a source of protein.

● Microorganisms like bacteria and fungi are cultured to obtain a number of products, like antibiotics, ethanol and enzymes which are beneficial for human beings.

● Microorganisms are also being used for the production of recombinant molecules such as insulin, hepatitis B vaccine, growth hormones and interferons.

● Production of alcohol and acids are examples of primary metabolic products, whereas antibiotics are examples of secondary metabolites produced by different microorganisms.

● Microbial metabolism has also been exploited for the microbial production of vitamins.

● Extraction of metals from ores and treatment of liquid waste are also examples where microbial metabolism is used to convert unsuitable substrates to useful products.

● Model systems are provided for studying the physiology and biochemistry of cells.

● Cell cultures have revealed the existence of a so-called cytoskeleton in mammalian cells, which gives the cell its shape and regulates a variety of biochemical activities.

● The effects of drugs and toxic compounds on the cells can be tested.

● In pharmacological studies, the cell culture is helpful as drug screening can be carried out in the lab.

● Studies on cancer can be carried out by testing the action of carcinogens and mutagens.

● Cell culture has been used to manufacture biological compounds on a large scale. These compounds include vaccines for polio, measles, mumps, rubella, and chickenpox.

Tissue Culture

What is tissue culture?

● In tissue culture, a piece of tissue extracted from an organism is isolated and grown in an artificial environment.

● In tissue culture, the environment for the growth of the tissue is controlled that allows manipulation.

● In tissue culture, the source can be a single cell (in that case it becomes cell culture), a group of cells, part of an organ or the whole organ.

● The factors introduced in the culture medium bring about changes in the cell population, size or form or function.

● Some tissues are manipulated to exhibit some specific activity.

Application of Tissue Culture

● It has helped in gaining knowledge about the basic composition and form of the different cell types.

● Research has permitted the study of biochemical functions of the cell, cell genetics and cell reproduction, cell nutrition and intercellular communication.

● Studies have helped to identify the effect of infectious agents on the cell types, enzyme deficiencies, and chromosomal abnormalities.

● Tissue culture also permits the study of normal cells and abnormal cells like cancerous cells and reveals the difference between these cells.

● Tissue-culture studies have revealed the genetic factors and abnormality or mutation in genes that give rise to hereditary diseases.

● The nature of certain cancers has been elucidated by the discovery of specific genes and chromosomal aberrations that are associated with the disease.

Plant Tissue Culture

● Plant tissue culture is the development of a new seedling from either a single plant cell or a plant tissue or part of the plant like a root in controlled laboratory conditions.

● Cells, tissues or part of plant organs used to grow a plant in the medium are called explant.

● The culture medium may be liquid, solid or semi-solid and contains adequate nutrients for growing plants in the lab.

Applications of Plant Tissue Culture:

● Micropropagation - The plant material is rapidly multiplied to produce a progeny of plants. Usually, the commercially important plants are micro propagated.

● Secondary metabolites from plants have important commercial applications. e.g. in healthcare, food, flavor and cosmetics industries.

● Plant tissue culture can help with large scale production of metabolites by introducing factors in the growth medium that activate production of secondary metabolites.

● Anther culture produces haploid or double haploid plants.

Protoplast culture:

● Protoplasts are cells in which the cell wall has been removed, but the plasma membrane remains intact.

● This protoplast can be cultured to produce clones- these clones are called somaclones which are plants produced through tissue culture that are genetically identical to the individual plant used for explant.

● Two different protoplasts from different species can be fused to give rise to somatic hybrids.

● In some protoplasts, a different gene can be introduced to form a transgenic plant.

Production of somaclonal variants:● Somaclonal variation refers to genetic variability found in plants produced

through tissue culture. ● Production of synthetic/ artificial seeds.● Obtaining the whole plant from isolated cells. ● Production of plants that do not produce seeds or those plants which produce

seeds or spores after a very long time. Such plants can be produced in a lab at a mass scale.

● Dormancy in seeds is a natural phenomenon. Seeds only germinate when favorable conditions appear. Dormancy of seeds can be broken in the lab by providing the favorable conditions artificially.

Tissue Engineering

● Recent advances in the fields of cell biology, biomedical engineering and materials science have given rise to the interdisciplinary field of tissue engineering.

● The aim of tissue engineering is to supply body parts for repair of damaged tissue and organs, without causing an immune response or infection or mutilating other parts of the body.

● Tissue engineering potentially offers dramatic improvements in low-cost medical care for hundreds of thousands of patients annually.

● Large-scale culturing of human or animal cells including skin, muscle, cartilage, bone, marrow, endothelial and stem cells may provide substitutes to replace damaged components in humans.

● Such implants could function like neo-organs in patients without triggering immune responses.

● Genetically-modified animals may also provide a source of cells, tissues, and organs for xenografts.

Stem Cell Technology

● Stem cells are characterized by their ability to renew themselves through mitosis cell division and differentiate into a diverse range of specialized cell types.

● Stem cells are found in all multicellular organisms.

● Stem cells are like good shares in the stock market which can either be multiplied (self renewal) by getting bonus shares or sold to buy goods (differentiate).

● Tissues like skin, blood and intestinal epithelium are subject to continuous renewal throughout life and must maintain an adequate number of cells (stem cells) that retain the potential to proliferate to make good such losses.

● The most well studied process has been the formation of blood cells (haematopoiesis).

● It was known in case of mouse that haematopoiesis occurs in the spleen and bone marrow.

● In a human being about, 100,000 haematopoietic stem cells produce one billion RBC, one billion platelets, one million T cells, one million B cells per Kg body weight per day.

● The field of stem cell research was established in the 1960s by Ernest McCulloch and James Till at the University of Toronto, Canada.

● The two broad types of mammalian stem cells are:

○ Embryonic stem (ES) cells that are isolated from the inner cell mass of blastocysts, and

○ Adult stem cells that are found in adult tissues.

● The ES cells are pluripotent and can differentiate into all types of specialized tissues.

● The adult stem cells are multipotent (lineage restricted) and act as a repair system for the body by maintaining the normal turnover of regenerative organs, such as blood, skin, or intestinal tissues.

● Stem cells are now routinely grown and transformed into specialized cells such as muscles or nerves through cell culture and used in medical therapies.

Application of Stem cell:

● The stem cells are useful in many medical conditions where cells are either dead or injured or abnormal, such as:

○ Leukemia (cancerous blood cells).

○ Heart disease, heart attack (cardiac tissue damage).

○ Paralysis (spinal cord injury).

○ Alzheimer's, Parkinson's, Huntington's (dead brain cells).

○ Burns (damaged skin cells).

Applications of Biotechnology

1. Gene Therapy

2. Pharmacogenomics

3. Genetic Testing

4. DNA Profiling/ DNA Fingerprinting

5. Biofertilizer

6. Genetically Modified Food

7. Bioremediation

8. Biosensors

1. Gene Therapy

● Genes are the basis of heredity function.

● Genes carry specific sequences of bases that encode proteins.

● Proteins carry major functions in many organisms and are a backbone of the metabolic processes that sustain life.

● Any damage to the gene or mutation alter the encoded proteins.

● Sometimes, the altered proteins are unable to carry out their normal functions.

● This gives rise to genetic disorders.

● Gene therapy is a technique for correcting the defective genes that cause genetic disorders.

● In gene therapy either the normal gene may be inserted into the genome to replace a non-functional gene or homologous recombination can be carried to swap the places of an abnormal gene with the normal gene.

● Selective mutation can be carried out for reversing the mutation of the gene so that the gene starts functioning normally.

2. Pharmacogenomics

● Pharmacogenomics combines pharmacology (the study of drugs) and genomics (the study of the genome and the function carried out by genes).

● Thus, pharmacogenomics studies how the genome affects response to a drug.

● The main aim of pharmacogenomics is to develop safe medications and doses that are customized to the genetic makeup of the person so that the drug is effective to the maximum.

Applications of Pharmacogenomics:

● Development of tailor-made medicines according to the person’s genome to maximize therapeutic effects and reduce damage to healthy cells.

● Determining accurate and appropriate drug dosages to maximize metabolism of the drug in the body. This decreases the likelihood of overdose.

● The genes associated with diseases can be targeted for the development of effective new therapies.

● Development of safer vaccines using genetically engineered organisms. Development of safer vaccines ensures that immune response is elicited without the risk of infection.

3. Genetic Testing

● In genetic testing, a scientist directly examines a patient's DNA sample for mutated sequences.

● Genetic tests have been used to detect genetic disorders like cystic fibrosis, sickle cell anemia, and Huntington's disease.

● It has also been used to detect genetic mutations that cause breast, colon or ovarian cancers

● Screening of newborns’ DNA to detect any congenital disorder and pre-natal diagnostic screening.

● Pre-symptomatic testing in individuals at high risk of developing cancers, especially in cases where there is a family history of a particular cancer.

Genetic Testing has been employed for:

● Identification of carriers- Carriers are individuals who contain the gene for a genetic disease like hemophilia but themselves are unaffected as the disease needs two copies of the gene to get expressed.

● Conformational diagnosis can be done in case of patients showing some symptoms for a disease.

4. DNA Profiling / DNA Fingerprinting

● Chemically, DNA of all humans is the same - A double-helical structure made of a Sugar-Phosphate backbone in which the bases, adenine (A), guanine (G), thymine (T) and cytosine (C) are found.

● Base A of one strand forms a hydrogen bond with the T of another strand and the G of one strand forms a hydrogen bond with the C.

● The difference between individuals arises due to the difference in the order in which these bases are arranged.

● Millions of base pairs are found in each individual's DNA and every person has a different sequence.

● To differentiate individuals, scientists use a shorter method, based on repeating patterns in DNA.

● These repetitive ("repeat") sequences are highly variable and are called Variable Number Tandem Repeats (VNTRs), particularly Short Tandem Repeats (STRs).

● Differences in these variable regions between people are known as polymorphisms.

● An individual inherits a unique combination of polymorphisms from parents.

● An example of repetitive DNA is GATA repeats on a specific location on chromosomes.

● The GATA sequence is differently organized in different individuals.

● An individual may have no repeat of GATA, another individual may have 10 GATA repeats at the same location on a particular chromosome.

● Using DNA fingerprinting the variation in GATA repeats among individuals can be detected and individuals can be identified.

Applications of DNA Fingerprinting:● It has become a very important part of forensics and crime investigation.● Establishing biological parentage and resolving family disputes. ● Medical diagnosis● Sex-selection in animals● Defense records● Authenticity of consumer products● Pedigree analysis● Seed-stock identification● Wildlife conservation

5. Bio-Fertilizer● Biofertilizers are preparations containing living microorganisms or latent

cells which are applied to plant seed, root or soil and upon application mobilize the availability of nutrients.

● The biological activity of microorganisms not only help in better nutrient uptake by the plant, but also contribute to soil health by building up microflora in the soil.

● The nutrients are added to the soil when the microorganisms perform nitrogen fixation to form nitrogenous compounds and solubilize phosphorus.

● Biofertilizers used are bacteria like Rhizobium, Azotobacter, Azospirillum and Blue Green Algae (BGA), also called cyanobacteria.

Why use Bio-fertilizers?

● They reduce dependence on chemicals and can replace chemical preparations containing nitrogen and phosphorus by 30%.

● The organic nature of biofertilizers helps in keeping the soil healthy and safeguards the sustainability of environment being eco-friendly.

● Help in safeguarding the sustainability and the health of the soil.

● Microorganisms in the biofertilizer build organic matter in the soil.

● The microorganisms in biofertilizers restore the soil's natural nutrient cycle and build soil organic matter.

● They stimulate plant growth and can increase crop yield by 25%.

6. Genetically Modified (GM) Food

● Genetic Engineering of food (especially crops) is carried out for various purposes, mainly for making them resistant to insects and viruses and more able to tolerate herbicides or drought conditions.

● Some crops have been modified to increase their nutritive value, better appearance and texture.

Why GM Food?

For Nutritional Enhancement:

Genetic engineering can be used to increase the amount of essential nutrients like vitamins in food crops.

Improved Yield:

Genetic engineering can be used to introduce one or two genes in a highly developed crop variety to impart a new character that would increase its yield

Reduced Vulnerability of Crops to Environmental Stresses:

● A plant gene, At-DBF2, from thale cress, a tiny weed is often used for plant research because it is very easy to grow and its genetic code is well mapped out.

● This gene was inserted into tomato and tobacco cells and the cells were able to withstand environmental stresses like salt, drought, cold and heat, far more than ordinary cells.

● Transgenic rice plants that are resistant to rice yellow mottle virus (RYMV) have also been created.

Increased Nutritional Qualities & Quantity of Food Crops:

● Golden rice is a variety of rice (Oryza sativa) produced through genetic engineering to biosynthesize beta-carotene, a precursor of pro-vitamin A in the edible parts of rice.

● Golden rice was developed as a fortified food to be used in areas where there is a shortage of dietary vitamin A.

● In 2005 a new variety called Golden Rice 2 was announced which produces up to 23 times more beta-carotene than the original variety of golden rice.

● Improved Taste, Texture or Appearance of food.

● Biotechnological methods can be used to reduce the process of spoilage so that fruits and vegetables can have a reasonable shelf life.

Reduced Dependence on Fertilizers, Pesticides and Other Agrochemicals:

● Bacillus thuringiensis (Bt) is a soil bacterium that produces a protein with insecticidal qualities.

● There are several Bt toxins and each one is specific to certain target insects.

● Bt-corn is now commercially available in a number of countries to control corn borer (a lepidopteran insect), which is otherwise controlled by spraying (a more difficult process).

● The introduction of herbicide tolerant crops has the potential of reducing the number of herbicide active ingredients used for weed management, reducing the number of herbicide applications made during a season, and increasing yield due to improved weed management and less crop injury.

Production of novel Substances in Crop Plants:

● Biotechnology is being applied for novel uses other than food.

● For example, oilseed can be modified to produce fatty acids for detergents, substitute fuels and petrochemicals.

● Potatoes, tomatoes, rice, tobacco, lettuce, safflowers, and other plants have been genetically-engineered to produce insulin and certain vaccines.

● If future clinical trials prove successful, the advantages of edible vaccines would be enormous, especially for developing countries.

7. Bioremediation

● Bioremediation can be defined as any process that uses microorganisms, fungi, green plants or their enzymes to return the natural environment altered by contaminants to its original condition.

● Biotechnology applies the natural mechanisms for cleaning up the environmental contamination.

● Research is ongoing to find various microorganisms for clearing up harmful chemicals often present at contaminated industrial sites.

● Also, use of genetic engineering to develop microbial strains having increased ability to metabolize specific chemicals, such as hydrocarbons is being undertaken.

● The oil industry uses bacteria to clean up pollution created by spills and underground leaks and to clean up waste products from oil production.

● To remediate wastewater faster and more efficiently, researchers developed a reactor that uses oil-degrading bacteria.

● The reactor uses bacteria from the Pseudomonas family.

8. Biosensors

● A biosensor comprises a sensitive biological component like cell receptors, tissue, enzymes etc. which is combined with a physical or chemical detector component.

● A common example of a commercial biosensor is the blood glucose biosensor, which uses the enzyme glucose oxidase to break blood glucose down and help create an electric current whose measure can give the concentration of glucose.

● Many biosensors use organisms that can detect toxic substances at much lower concentrations than humans can detect.

● Such biosensors will be useful for environmental monitoring to detect the presence of toxins, trace gas detection and in water treatment facilities.

Applications of Biosensors:

● Detection of pesticides and contaminants in river or lake water.

● Determining levels of toxic substances before and after bioremediation.

● Determining drug residues in food.

● Food analysis to check the presence of toxins or adulteration.

Human Genome Project

● The Human Genome Project (HGP) was an international scientific research project which was a collaboration between the US, UK, France, Germany, Japan and China.

● It formally began in the year 1990 and was completed in 2003.

● The Human DNA sequence is stored in GenBank which is the database developed by the U.S. National Centre for Biotechnology Information and sister organizations in Europe and Japan.

● Computer programs have been developed to analyze the complex data.

Why GHP?

● Genome refers to the entire genetic makeup of an individual.

● The genome stores all the hereditary information.

● The study of the genome is the key to understand the effects of variation of DNA among individuals.

● It is particularly helpful for medicine where knowledge of the genes and the result of malfunctioning of the genes can help to diagnose, treat and even prevent a number of genetic disorders.

Goals of HGP:

● Identification of all the genes in human DNA estimated to be around 20,000-25,000 in number.

● Determining the sequences of the 3 billion chemical base pairs making up the human DNA.

● Storage of collected information in databases.

● Improving tools for analysis of the data from the project.

● Transferring related technologies to the private sector.

● Addressing ELSI- Ethical, Legal, and Social Implications (ELSI) that may arise from HGP.

Applications of HGP:

● Gene therapy, early detection of genetic predispositions to disease, drug designing, researching the damage to genes caused by exposure to mutagens like chemicals and radiation.

● DNA forensics - DNA fingerprinting for crime investigation and resolving disputes about biological parentage, matching organ donor DNA with the recipient DNA for the success of transplantation.

● Energy and environmental applications that include creating new biofuels, using microbial genomics to identify microorganisms that can detect pollutants or offer bioremediation.

● Agriculture where GM crops modified for producing disease resistant, pest resistant or drought resistant crops. It also involves producing healthy breeds of farm animals.

LUCA

● The last universal common ancestor (LUCA) is the most recent population of organisms from which all organisms now living on Earth have a common descent.

● LUCA is the most recent common ancestor of all current life on Earth.

● LUCA should not be assumed to be the first living organism on Earth.

● The LUCA is estimated to have lived some 3.5 to 3.8 billion years ago (sometime in the Paleoarchean era).

● The composition of the LUCA is not directly accessible as a fossil but can be studied by comparing the genomes of its descendants, organisms living today.

● The earliest evidence of life on Earth is biogenic graphite found in 3.7 billion-year-old metamorphosed sedimentary rocks discovered in Western Greenland and microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia.

● Charles Darwin proposed the theory of universal common descent through an evolutionary process in his book “On the Origin of Species” in 1859.

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