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13.13: Introduction to Biotechnology Applications - Biology

13.13: Introduction to Biotechnology Applications - Biology


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What you’ll learn to do: Identify societal uses of biotechnology

This video provides an introduction to some of the newest breakthroughs in biotechnology: biofuel, health, and agriculture.

A link to an interactive elements can be found at the bottom of this page.

In this outcome we will discuss the ways biotechnology is used in our society.


MCQs of Introduction Of Biotechnology

A. Ribosomes contain RNA nucleotides and amino acids
B. A messenger RNA molecule has the form of a double helix
C. The uracil nucleotide consists of the uracil nitrogen base, a deoxyribose sugar and a phosphate group
D. In eukaryotes, DNA is manufactured in the nucleus and RNA is manufactured in the cytoplasm
E. None of the above

10. Mold Penicillium was discovered by the scientist Alexander Fleming in which year?

A. 1931
B. 1928
C. 1935
D. 1939
E. None of the above

11. Which of the following is the example of red biotechnology?

A. Industrial catalyst
B. Pesticides
C. Antibiotics
D. Bt corn
E. None of the above

12. Which of the following scientist was discovered Mold Penicillium?

A. Alexander Fleming
B. Louis Pasteur
C. Charles Darwin
D. Chaim Weizmann
E. None of the above


For the computational exercises, MATLAB® will be used intensively.

By the end of the course, the student must be able to:

  • Formulate mass balances of reaction networks
  • Solve mass balance equations using linear programing solvers
  • Analyze papers on modeling and analysis of biological networks
  • Assess / Evaluate alternative methods for the study of biological networks
  • Construct kinetic models of biological reactions

Biotechnology: Various Applications of Biotechnology

The recombinant DNA technological processes have made great impact in the area of healthcare by mass production of safe and more effective therapeutic drugs.

Further, the recom­binant therapeutics does not induce unwanted immunological responses. Now about 30 recombi­nant therapeutics have been approved for human use all over the world. In India, 12 of these are presently being marketed.

Genetically Engineered Insulin:

Role of Sharpy-Shafer, Banting, Best and Macleod. Sharpy-Shafer (1916) first expressed the opinion that diabetes is caused by failure of the islets of pancreas to secrete a substance named by him as insulin. Insulin is secreted by the Beta cells of the islets of Langerhans of the pancreas. In 1921, Banting and Best succeeded in preparing a pure extract of insulin from the pancreatic islets of a dog with the help of Macleod. Banting and Macleod won the 1923 Nobel Prize in Medicine or Physiology.

They demonstrated that administration of insulin could cure diabetes in human beings, earlier, insulin for curing diabetes used to be extracted from pancreas of slaughtered pigs and cattle. This insulin is slightly different from human insulin and brings about some undesirable side effects such as allergy.

Structure of Insulin:

Human insulin is made up of 51 amino acids arranged in two polypeptide chains, A having 21 amino acids and В with 30 amino acids. The two polypeptide chains are interconnected by two disulphide bridges (Fig. 12.9) or S-S linkages. An S-S linkage also occurs in A chain. The hormone develops from a storage product called pro­insulin.

Proinsulin has three chains, A, В and С. С -chain with 33 amino acids is removed prior to insulin formation. Bacteria cannot be made to synthesise insulin from its gene because of the presence of introns. Bacteria do not possess enzymes for removing intron mediated transcription.

How Insulin is Synthesized?

As stated earlier insulin is produced by the Beta cells of the islets of Langerhans of the pancreas. The gene for this protein synthesis is located on chromosome 11. In mammals, including humans, insulin is synthesized as a pro-hormone (like a proenzyme, the prohormone also needs to be processed before it becomes a fully mature and functional hormone) which contains an extra stretch called the С peptide.

This С peptide is not present in the mature insulin and is removed during maturation into insulin. The main challenge for production of insulin using rDNA technique was getting insulin assembled into a mature form. In 1983, Eli Lilly an American company, first prepared two DNA sequences corresponding to A and В chains of human insulin and introduced them in plasmids of Escherichia coli to produce insulin chains. Chains A and В were produced separately, extracted and combined by creating disulfide bonds to form human insulin (humulin).

Molecular structure of insulin was worked out by Sanger. Tsan synthesised human insulin first time.

Production of Human Insulin:

It involves essentially the following stages:

(i) Isolation of Donor or DNA segment:

A useful DNA segment is isolated from the donor organism.

(ii) Formation of Recombinant DNA (rDNA):

Both the vector and donor DNA seg­ments are cut in the presence of restriction endonuclease. In the presence of ligase DNA segments of both are joined to form rDNA.

(iii) Production of Multiple Copies of rDNA:

Next step in the process is production of multiple copies of this recombinant DNA.

(iv) Introduction of rDNA in the recipient organism:

This rDNA is inserted into a recipient organism.

(v) Screening of the trans­formed cells:

The recipient (host) cells are screened in the presence of rDNA and the product of donor gene.

The transformed cells are separated and multiplied, an economical method for its mass production. The various steps and their sequence for the pro­duction of human insulin are depicted in Fig. 12.11.

Dr Saran Narang, a scientist of Indian origin, working in Ottawa, Canada was involved in cloning of insulin gene.

i. The most famous of the dogs Banting and Best used was one called “Marjorie”.

ii. The first patient of diabetes to be administered insulin was 14- year old Leonhard Thompson.

iii. Insulin cannot be orally admin­istered to diabetic patient be­cause it degrades in the alimen­tary canal.

iv. Banting was born on Novem­ber 14th, 1891 hence 14th November is observed as “Diabetic Day”.

v. In 1982 insulin (Eli Lilly’s Humulin) was the first product made genetically engineered bacteria to be approved for use in Britain and the U.S.A.

Gene Therapy:

Gene therapy is the technique of genetic engineering to replace ‘a faulty gene’ by a normal healthy functional gene.

Types of Gene Therapy:

(i) Germline Gene Therapy:

In this type of gene therapy germ cells, i.e., sperms or eggs (even zygotes) are modified by the introduction of functional genes, which are ordi­narily integrated into their genomes.

(ii) Somatic Cell Gene Therapy:

In this type of gene therapy, the gene is introduced only in somatic cells.

Only introduction of a new gene into the somatic cells is allowed at present. Genetic modification in the germ cells of the offspring is not permissible.

Diseases and Gene Therapy:

The diseases for which scientists are making serious attempts to control through gene therapy are severe combined immunodeficiency (SCID) disease, Duchenne muscular dystrophy and cystic fibrosis. These disorders are mainly due to single gene defects. Cancer, cardiovascular diseases, diabetes, hypertension, arthritis, sickle cell anaemia, etc. are complex genetic disorders. However, the day is not far off when these diseases can be cured through gene therapy.

Example. Adenosine Deaminase (ADA) Deficiency:

The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency. This enzyme is very important for the immune system to function. ADA deficiency can lead to severe combined immune deficiency (SCID). SCID is caused due to defect in the gene for the enzyme adenosine deaminase.

In some children ADA deficiency can be cured by bone marrow transplantation. However, in others it can be treated by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But in both approaches the patients are not completely cured.

Because these patients do not have functional T-lymphocytes, they cannot provide immune responses against invading pathogens.

As a first step towards gene therapy (Fig. 12.12), lymphocytes, a kind of white blood cells, are extracted from the bone marrow of the patient and are grown in a culture outside the body. A functional ADA cDNA (using a retroviral vector) is then introduced into these lymphocytes, which are re injected to the patient’s bone marrow.

But as these cells do not always remain alive, the patient requires periodic infusion of such genetically engineered lymphocytes. However, if the isolated gene from bone marrow cells producing ADA is introduced into cells at early embryonic stages, it can be a permanent cure.

Molecular Diagnosis (Diagnosis of Disease):

It is well known that an early diagnosis and understanding its pathophysiology (symp­toms, etc.) are very important for the effective treatment of the disease. Using conventional methods of diagnosis (serum and urine analysis, etc.) early detection is not possible. Recombinant DNA technology, Polymerase Chain Reaction (PCR) and Enzyme Linked Immunosorbent Assay (ELISA) are some of the techniques that serve the purpose of early diagnosis.

The molecular probes are usually single stranded pieces of DNAs (sometimes RNAs) labelled with radio isotopes such as 32p. Molecular probes are available for many genetic disorders such as Duchenne muscular dystrophy cystic fibrosis, Tay-Sachs disease.

The analytical techniques used for the identification of a specific DNA, an RNA or a protein from thousands of each are collectively called blotting technique. In Southern blotting extraction of DNA from the cells (say leucocytes) occurs. Latter on labelled DNA hybrid complexes are formed which can be identified on exposure to X-ray film.

In North­ern blotting RNA is identified by labelled DNA or RNA probe. In Western blotting, protein is identified with the help of labelled antibody probe. The radioactively labelled DNA probes are formed.

Presence of a pathogen (bacteria, viruses, etc.) is usually suspected only when the pathogen has produced a diseased symptom. By this time the number of pathogens is already very high in the body, but very low count of a bacteria or virus (when the symptoms of the disease are not yet visible) can be detected by multiplication of their nucleic acid by PCR.

PCR can detect very low amounts of DNA. PCR is now usually used to detect HIV in suspected AIDS patients. It is also used to detect mutations in genes in suspected cancer patients. It is a good technique to identify many other genetic disorders.

A single stranded DNA or RNA joined with a radioactive molecule (probe) is allowed to hybridize to its complementary DNA in a clone of cells. It is followed by detection using autoradiography. The clone having the mutated gene will not appear on the photographic film, because the probe will not have the complementarily with the mutated gene.

ELISA is based on the principle of antigen-antibody interaction. It can detect very small amount of protein (antibody or antigen) with the help of enzyme (e.g., peroxidase or alkaline phosphatase). Infection by pathogen can be detected by the presence of antigens such as proteins, glycoproteins, etc. or by detecting the antibodies synthesised against the pathogen.

Steriods:

Steroids are crystallisable lipids of high molecular weight. They consist of one 8-carbon ring and three 6-carbon rings. Steriods are found in both plants and animals. Murray and Peterson (1950) observed that the fungus Rhizopus stolonifer could bring about hydroxylation of steroids. Important uses of steroids are:

(i) Cortisone and its derivatives (prednisone and prednisolone) are effective in the treat­ment of rheumatoid arthritis.

(ii) Steroid hormones are known to be regulators of metabolism in the animal or human body.

(iii) Steroid treatment is given to suppress immune responses in patients with autoim­mune diseases or persons who have had organ transplants.

(iv) Prednisolone is used as an anti-inflammatory drug.

(v) Oestrogens and progesterone’s are employed in the preparation of oral contracep­tives (birth-control pills).

Vaccines:

Vaccines are either attenuated (live but weak) or dead (inert) agents of disease which when administered into a healthy person provide temporary or permanent immunity to that particular disease. The term vaccine was introduced by Edward Jenner (1790) who worked on small pox.

Later, Jenner’s findings were extended by Louis Pasteur (1879) to other infective diseases such as anthrax, rabies and cholera. Pasteur established the scientific basis of vaccination. Recently some second generation vaccines have been prepared with the help of genetic engineering technique against hepatitis-B and herpes virus.

They are more uniform in quality and produce less side effects as compared to ‘first-generation the vac­cines. Now-a-days production of ‘third generation vaccines’ called synthetic vaccines, are being tried. Antifertility vaccines have also been developed.

The genes encoding antigenic proteins can be isolated from the pathogens and expressed in plants. Such transgenic plants or their tissues producing antigens can be eaten for vac­cination/immunization. These are called edible vaccines.

The expression of such antigenic proteins in crops like banana and tomato are useful for immunization of humans because banana and tomato fruits can be eaten raw. The edible vaccines that are produced in transgenic plants have great advantages like less storage problems, easy delivery system by feeding and low cost as compared to the recombinant vaccine.

Human Growth Hormone (hGH)—Somatotropin:

hGH is secreted by the anterior lobe of pituitary gland. Secretion of hGH is regulated by two other hormones secreted by hypothalamus. These hormones are:

(i) somatotropin releasing hormone which stimulates the anterior lobe of pituitary gland to release soma­totropin or growth hormone

(ii) Somatostatin or growth inhibiting hormone which inhib­its the secretion of growth hormone from the anterior lobe of pituitary gland. Deficiency of somatotropin in about 3% cases is hereditary. It has been estimated to about 1 child in 5,000. hGH is very useful to the children born with hypopituitarism which is a form of dwarfism. It is caused by less secretion of hGH from the anterior lobe of pituitary gland. hGH is also helpful in “healing of injuries”.

Bovine Growth Hormone (BGH):

This hormone has veterinary uses. For example, injecting a cow with bovine growth hormone (BGH) can increase milk production by as much as 25%. BGH also improves beef yield in cattle (10-15% increase in body mass).

Forensic Medicine (Identifica­tion of Murders, Rapists, etc.):

Biotechnology has proved to be a boon in solving crimes, legal disputes, etc. Establishing the identity of victims (e.g., of murder, accidents, etc.), criminals (e.g., in cases of rape, murder, etc.), father (in cases of paternity dispute) etc. is unable to solving the problems of crimes/cases. A biotechnological procedure, called DNA finger-printing or DNA profil­ing, is a highly sensitive, fool-proof, absolutely accurate and extremely versatile approach to this problem.

Monoclonal Antibodies:

Antibodies derived from a single clone of cells which recognize only one kind of antigen, are called mono­clonal antibodies. The technique of producing monoclonal antibodies by Fusing normal antibody-producing cells with cells from cancerous tumors was introduced by Georges Kohler and Cesar Milstein in 1970. The major steps in the production of monoclonal antibodies with hybrid cultures are mentioned below:

(i) First of all a mouse rat or some other animal is injected with specific antigen (against which the antibodies are required).

(ii) The animal starts developing antibodies against the antigen in B-lymphocyte cells in spleen,

(iii) The spleen of animal is removed and its B-lymphocyte cells are isolated

(iv) Similarly, the cells producing bone marrow cancer (myeloma cells) are isolated. These cells should not be able to synthesise their own nutrients,

(v) The two types of cells (i e myeloma cells and antibody-producing cells) are made to fuse in cultures. The fused cells are called hybridomas.

(vi) The entire culture is shifted to a medium deficient in the nutrient needed by the myeloma cells where myeloma cells cannot survive. In this medium all the un-fused myeloma cells die and only hybridoma cells survive, (vii) The surviving hybridoma cells are allowed to multiply separately and each clone is tested for its ability to produce a desired antibody.

(viii) The clones which show positive results are isolated and cultured for large scale production of the antibody.

Monoclonal antibodies are highly specific for specific antigens and can be easily cultured outside the body. These antibodies are, therefore, more effective and ideal for diagnosis of some specific diseases. One of the most effective applications of monoclonal antibodies is immune suppression for kidney transplantation.

Interferons (IFNs):

Interferons are the antiviral glycoproteins (called cytokines) functioning as immune regulators or lymphokines produced by the infected cells in response to viral infections (discovered in 1957 by Alec Issacs and Jean Lindenmann). These proteins are produced by most body cells on exposure to viruses.

They diffuse to neighbouring cells and trigger a reaction that neutralizes the particular viruses. Some interferons also neutralize other viruses and, therefore, prevent viral infections. They also inhibit cellular proliferation and modulate the immune system of the organism.

There are three major classes of interferons

This kind of interferon is produced when leucocytes and lymphocytes are exposed to virus.

These are produced by fibroblasts, epithelial cells, macro- phytes and leucocytes in response to viral infection.

These are produced by T-lymphocytes induced by antigenic stimulation.

Until recently the only source of interferons was human white blood cells or virus infected human cells grown in tissue culture. Production of human interferon by cloning of genes in colon bacilli was started in 1980 by two American scientists Gilbert and Weissmann.

The work triggered a wave of experimentation resulting in the production of interferons in large amounts by recombinant DNA technology. The interferons (particularly IFN-a) are used on a significant scale for the treatment of hepatitis-B. Interferons are also being tested for the treatment of cancer and some viral diseases including AIDS.

Use of Polymerase Chain Reaction (PCR):

PCR is a technique by which any piece of DNA can be quickly amplified (copied many times) without using cells. The DNA is incubated in a test tube with a special kind of DNA polymerase enzyme, a mixture of deoxyribonuleotides for use as raw material, and short pieces of synthetic single stranded DNA to serve as primers for DNA synthesis. PCR can make billions of copies of a DNA segment in a few hours.

To clone a DNA segment in bacteria takes days. When the source of DNA is scanty or impure, it can be amplified by PCR technique. Amplification can make the identification of DNA easier. Since the sequence of HIV DNA is known, its amplification by PCR can help detect HIV DNA in blood or tissue samples.

This is often the best way to detect infection. DNA from single embryonic cell is amplified by PCR for rapid prenatal diagnosis of genetic disorders. DNA from tiny amounts of blood, tissue or semen found at the site of crime can be amplified to facilitate its iden­tification.

DNA technology can help identify individuals with genetic disorders before the appearance of symptoms, even before birth. It is also possible to identify symptomless carriers of potentially harmful recessive alleles, such as of haemophilia, phenylketonuria (PKU). PCR is also helpful in DNA fingerprinting.

Making a Choice of Baby’s Sex:

Recently techniques have also been developed which will not require preferential abor­tion but will allow preferential fertilization by male (carrying Y chromosome) or female (carrying X chromosome) determining sperms. There are techniques available now, which allow separation of sperms carrying Y chromosomes, from the ejaculate of a man (through Ericson’s method developed by R. Ericson of U.S.A) to be used for insemination of ovulating women.

This technique (using quinacrine stain) has been used with 80% success in 47 sperm centres in the world including one in Mumbai. Ericson has actually established a company named Gametrics Ltd, in California, U.S.A. which specializes in separating sperms with Y chromosome and hundreds of male children have been produced with its help.

Techniques have also been developed to separate sperms carrying X chromosome for artificial insemination leading to the birth of female children. This technique involves ‘sephadex gel column’ in which sperms with Y, being lighter are trapped in gel and those with X being heavier reach the bottom of the column, and can be used for inseminaton.

Production of Vitamins:

1. Vitamin B12 (Riboflavin):

Riboflavin is produced commercially by direct fermen­tation utilizing the fungus Ashbya gossypii. Fermentation conditions -pH 6.0 to 7.5, 4 to 5 days at 28-30°C, aerobic.

2. Vitamin B12 (Cobalamine):

Now a day’s vitamin B12 is produced by a direct fermentation utilizing streptomyces species such as Streptomyces griseus. Fermentation conditions -pH 6 to 7.7, 2 days at 26 – 28°C, aerobic.

3. Vitamin С (Ascorbic Acid):

Vitamin С was first recognized when in 1747, Scottish naval surgeon James Lind discovered that something in Citrus foods prevented scurvy. In 1928 Albert Szent-Gyorgyi, a much admired biochemist, was the first to isolate vitamin С (ascorbic acid). He later won the 1937 Nobel Prize in Physiology and Medicine for other work.

Vitamin С was the first vitamin to be synthesized artificially in a process invented by Dr. Tadeusz Reichstein, of the Swiss Institute of Technology in Zurich in 1939. Vitamin С is produced by utilizing Gluconobacter oxydans. Fermentation conditions -pH 7, 45 hours at 30°C, aerobic.

4. Vitamin A (Р-Carotene):

P-carotene is produced by members of choanephoraceae family of phycomycetes. Phycomyces blakesleeanus, Choanephora cucurbitarum and Blackeslea trispora have been extensively studied for their ability to produce P-carotene.

Applications of Recombinant DNA Technology/Genetic:

1. Molecular Analysis of Diseases:

DNA research has helped in understanding the molecular basis of diseases like sickle cell anaemia, thalassemias, etc.

2. Production of Proteins in Abundance:

Using recombinant DNA technique several proteins have been produced in abundance for curing the diseases. These are insulin, growth hormone, interferon’s, vaccines, erythroprotein and blood clotting factors.

3. Laboratory Diagnostic Application:

rDNA technology makes the diagnosis of many diseases (e.g., AIDS) simple and quick.

The genetic diseases like sickle cell anaemia can be cured through gene therapy.

5. Prenatal Diagnosis of Diseases:

DNA collected from the amniotic fluid surround­ing the foetus can be used for predicting the genetic diseases.

6. Application to Forensic Medicine:

rDNA technology has greatly helped to identify criminals by DNA fingerprinting and settle the disputes of parenthood of children.

7. Agricultural Application:

rDNA technology is used for developing transgenic plants which resist drought and diseases and increase their productivity. It improves quality of food.

8. Industrial Application:

Enzymes synthesized by rDNA technology are used to produce sugars, cheese and detergents.

9. Application to Animals:

It is used for developing test tube babies to overcome infertility and production of transgenic animals.

rDNA technique is of great use in joining several missing links in the evolution. This is done by amplifying the DNA of extinct animals.

Ethical Issues:

Ethics includes rules of conduct by which a community regulates its behaviour and decides as to which activity is lawful and which is not. Therefore, bioethics includes rules of conduct that may be used to regulate our activities in relation to the biological world.

The main bioethical concerns pertaining to biotechnology are briefly mentioned as follows:

(i) Introduction of a transgene from one species into another species violates the ‘integrity of species’,

(ii) Biotechnology may pose unforeseen risks to the environment, including risk to biodiversity,

(iii) Transfer of human genes into animals (and vice-versa) dilutes the con­cept of ‘humanness’,

(iv) When animals are used for production of pharmaceutical proteins, they are virtually reduced to the status of a ‘factory’,

(v) Use of animals in biotechnology causes great suffering to them,

(vi) Biotechnology is disrespectful to living beings, and only exploits them for the benefit of human beings.

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

1. Certain companies are being granted patents for products and technologies that make use of the genetic materials, plants and other biological resources that have long been identified, developed and used by farmers and common persons of a particular region/ country. There are numerous varieties of rice in India alone.

The diversity of rice in India is one of the richest in the world. Basmati rice is distinct for its unique aroma and flavour and 27 documented varieties of Basmati are grown in India. There is reference to Basmati in ancient books, as it has been grown for centuries. In 1997, an American company got patent rights on Basmati rice through the US Patent and Trademark Office.

This allowed the company to sell a ‘new’ variety of Basmati, in the US and abroad. 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. The patent extends to functional equivalents, implying that other people selling Basmati rice could be restricted by the patent.

2. Several attempts have also been made to patent uses, products and processes based on Indian traditional herbal medicines, e.g., turmeric neem. If we are not vigilant other countries/individuals may encash on our rich legacy.

Mostly the developed nations are rich financially but poor in biodiversity and traditional knowledge. In contrast the developing and the underdeveloped world is rich in biodiversity and traditional knowledge related to bio-resources. Traditional knowledge related to bio­resources can be exploited to develop modern applications.

Some nations are developing laws to prevent such unauthorised exploitation of their bio­resources and traditional knowledge.

3. The GM crops are fast becoming a part of agriculture throughout the world because of their contribution to the increased crop productivity and to global food, feed and fiber security, besides their use in health-care and industry.

4. The effect of GM crops on non-target and beneficial insects/microbes.

5. Transgenes may escape through pollen to related plant species (gene pollution) and may lead to the development of super weeds.

6. The GM crops may change the fundamental vegetable nature of plants as the genes from animals (e.g., fish or mouse) are being introduced into crop plants.

7. The safety of GM food for human and animal consumption, (e.g., GM food may cause allergenicity).

8. The effect of GM crops on biodiversity and environment.

9. The transgenes may move from plants to gut microflora of humans and animals and cause antibiotic resistance.

10. The GM crops may lead to the change in the evolutionary pattern.

11. Scientists cannot rule out the possibility of mutation or other biological damage.

12. The release of genetically engineered plants and animals in the environment could disturb the existing ecological balance.

13. The use of recombinant microorganisms for various commercial purposes can ac­cidentally create new infectious agents.

14. The main fear associated with the genetically engineered microorganisms is that they could escape from the laboratory into the environment with unpredictable fatal conse­quences. AIDS virus is supposed to be the outcome of such a research.

Bio-patent:

A patent is the right granted by a government to an inventor to prevent others from commercial use of his invention. When patents are granted for biological entities and for products derived from them, these patents are called biopatents. Primarily, industrialised countries, like U.S.A., Japan and members of European Union, are awarding Bio-patents. Bio-patents are awarded for (i) strains of microorganisms, (ii) cell lines, (iii) genetically modified strains of plants and animals, (iv) DNA sequences, (v) the proteins encoded by DNA sequences, (vi) various biotechnological procedures, (vii) production processes, (viii) prod­ucts and (ix) product applications. There is an opposition from social groups to biopatents. These objections are mainly ethical and political. Some biopatents are very broad in their coverage. For example, one patent covers “all transgenic plants of Brassica family”.

Cancelled patents on natural product inventions:

Patents on natural product inven­tions are subject to attack unless all public knowledge about the species in question and its use are fully disclosed. For example, a 1995 patent, “Use of Turmeric in Wound Healing”, was cancelled in 1998. The new evidence established that use of turmeric to promote wound healing had been known for generations in India.

Likewise, the 1986 plant claimed an ostensibly new, distinct variety of Banisteriopsis caapi, known in the Amazon as ayahuasca. However, new evidence establishes that the claimed plant is actually the wild uncultivated type, and is neither new nor distinctive. COICA, an organization of indigenous people, and the Amazon Coalition have requested re-examination of the ayahuasca patent, seeking to eliminate what is perceived as an immoral expropriation of their traditional and biological heritage. More such challenges can be antici­pated.

Significance of Bio-patents:

Bio-patent system allows private, monopoly rights over cells, genes, animals and plants. It means that people will not share vital research information because they are afraid that it will be patented by someone else. The people will not research in areas that are dominated by patents.

It will lead to research programmes dominated by patentability and profitability rather than need. It gives the patent holder monopoly control over resources for food and medicine. The important advantages of bio-patents are that they are a direct incentive for genetic engineering. The arguments in favour of bio-patents are primarily increased economic growth.

Genes, cells, microorganisms, plants and animals are not an invention and, therefore, should not be patented.

Bio-piracy:

Some organisations and multinational companies exploit and/or patent biological re­sources or bio-resources of other nations without proper authorisation from the countries concerned, this is called bio-piracy.

Historical Aspects:

Some examples of famous collecting trips are given below:

(a) The recorded history of international plant collecting missions goes back at least 3500 years when Egyptian rulers began bringing plants home after military expeditions.

(b) In the last century, the British Empire instituted regular plant collections. During the Voyage of the Beagle, Charles Darwin simply took what interested him, from the Galapagos and elsewhere, and brought it home.

(c) The Royal Botanical Gardens took rubber trees from Brazil, and planted them in South East Asia. They took cinchona seeds from Bolivia, in violation of national law, and planted them in India.

(d) Commodore Perry’s naval mission to Japan collected a wide variety of plants to bring back to the United States.

(e) More recently, the adventures of Richard Shultes during the mid-twentieth century have become a legend among ethnobotanists. He was able to befriend local shamans, who allowed him to collect thousands of voucher specimens of medicinal plants, hundreds of which had never previously been identified taxonomically.

None of these famous collecting trips was challenged on legal grounds. If done today, how would they be challenged?

Exploitation of Bio-resources:

Institutions and companies of industrialised nations are collecting and exploiting the bio-resources, as follows:

(i) They are collecting and patenting the genetic resources themselves. For example, a patent granted in U.S.A. covers the entire ‘basmati’ rice germplasm indigenous to our country,

(ii) The bio-resources are being analysed for identification of valuable bio-molecules. A bio-molecule is a compound produced by a living organism. The bio-molecules are then patented and used for commercial activities,

(iii) Useful genes are isolated from the bio-resources and patented. These genes are then used to generate commercial products,

(iv) The traditional knowledge related to bio-resources is utilised to achieve the above objectives. In some cases, the traditional knowledge itself may be the subject of a patent.

Brazzein:

Brazzein is a protein produced by a West African plant, Pentadiplandra brazzeana which is approximately 2,000 times as sweet as sugar. It is used as a low calorie sweetener. Local people have been using the super-sweet berries of this plant for centuries. But the protein brazzein was patented in U.S.A. The gene encoding brazzein was also isolated sequenced and patented in U.S.A. It is proposed to transfer the brazzein gene into maize and express it in maize Kernels. These Kernels will then be used for the extraction of brazzein. This development could have serious implications for countries exporting large quantities of sugar.

Examples of Bio-piracy:

The Thai Ministry of Science and its Biotech Institute has accused the British University of Portsmouth of “bio-piracy” as they have refused to return up to 200 strains of marine fungi that they collected in coastal waters and swamps around Thailand. Instead, Portsmouth University is reported to be in the process of selling the rights on “their” Thai fungi to a drug company for screening, as the fungi are believed to contain compounds for treating everything from AIDS to cancer- worth millions of pounds. Thailand insists that keeping the fungi without permission is in breach of international agreements.

India is a country rich in tradition, communal knowledge and expertise in natural medi­cines, spices, food preparations, biological pesticides and diverse agriculture. It is thus under siege from bio-pirates. Through patenting without consent, foreign companies have collared at least 22 plants for their beneficial derivatives. Patents have been taken out on plants such as black pepper (Piper nigrum), basmati rice (Oryza sativa), Indian mustard (Brassica campestris), pomegranate (Punica granataum), turmeric and neem. US, Japanese and German companies are the principal patenting pirates.

Nestle India has lined up a processing patent on cooked cereals, vegetable pulao and parboiled rice, at the Indian Patent Office, even though Indians have been making parboiled rice, often as a staple diet for centuries.

Bio-war:

War which is fought by bioweapons (biological weapons) against humans, their crops and animals is called biowar (biological war). Viruses, bacteria, fungi, spores and toxins can be used as bio-weapons (BW). Bio-weapons used during the 20th century are (i) 1942 Bntain developed strategic amounts of anthrax, (ii) 1940s Nazi prisoners infected with Rickettsia spp. hepatitis A, plasmodia spp. and treated with investigational vaccines and drugs, (iii) 1940s Nazi secret agent Reinhardt Heydrich assassinated with botulinum toxin, (iv) Germany used Bacillus anthracis (anthrax) to infect livestock and animal feed exported to Allies, (v) 1932-1945 Japan conducted research on B. anthracis, Shigella spp. V. cholera and Y. pestis.

US Bio-weapons Program can be mentioned as follows (i) In 1942 approximately 5000 bombs filled with B. anthracis produced, (ii) In 1950s program expanded during Korean War.

(iii) In 1955 human experiments with F. tularensis and C. burnetti. (iv) In 1949-1968 simulant organism released off coast of San Francisco and in New York City subway, (v) In 1969 US terminated offensive bio-weapons program, (vi) In 1972 Bio-weapons Convention and Treaty.

Diseases caused by bio-weapon agents are (i) Anthrax (ii) Small pox (iii) Plague (iv) Q- fever (fever, chills fatique, etc.) (v) Tularemia (it can occur in humans in two forms: ulceroglandular and typhoidal). (vi) Viral Encephalitis, (vii) Viral haemorrhagic fevers, (viii) Botulinum toxin (skeletal muscle paralysis).

Why are bio-weapons used? (i) Bio-weapons are low cost weapons, (ii) They cause far more casualties than chemical or conventional weapons. Once bio-weapon agents are released they are invisible, odourless and tasteless.

Protection against bio-weapons, (i) Use of respirator or gas mask, (ii) Protective shelter, (iii) Decontamination, (iv) Vaccination, (v) Antibiotics.

Biosafety Issues:

Measures taken to prevent any risk to plants, animals and microbes from transgenic organisms are known as biosafety. It was feared that genetically engineered microorganisms (GEMS) may disturb the ecosystem and its processes, in which they might be released. They may rapidly multiply and outcompete the native microbes. They may also transfer genes related to virulence or pathogenesis into bacterial population and, thereby increase their virulence. Similarly, genetically modified plants could pose biological and ecological risk.

Discussions on possible hazard of cloning recombinant DNA molecules began in the early 1970s. The main concerns were examined by a committee of National Academy of Sciences (USA) in 1974. The National Institute of Health (NIH), USA established the Recombinant Advisory Committee (RAC) in 1974. In Febmary 1975, a historic international meeting was convened at Asilomar, California.

The first NIH guidelines were prepared in 1975, they were more strict than the recom­mendations of the Asilomar Conference by 1981 most cloning experiments in E. coli, K-12, certain strains of Bacillus subtilis and Saccharomyces cerevisiae were considered exempt from other requirements of NIH guidelines. A major revision of the guidelines was done in 1982 containment levels were lowered and experiments that were previously prohibited were changed and approved by NIH.


Essay # 3. Advancement of Biotechnology:

This branch of biology is in use by mankind since very long. Numerous important achievements and advancements have been made by many eminent workers for this discipline.

A few of such important contributions by various workers in the field of biotechnology are enlisted below:

Biotechnology as a Multidisciplinary Activity:

Biotechnology is truly multidisciplinary (or interdisciplinary) in nature and it encompasses several disciplines of basic sciences and engineering. The science disciplines from which biotechnology draws heavily are Microbiology, Chemistry, Biochemistry, Genetics, Molecular Biology, Immunology, Tissue Culture and Physiology.

Recent advancements have led to a multidisciplinary’ applicability of biotechnology. Various areas in which this discipline is very frequently used on large scale are: agriculture, food and beverage industry, environment, medicines, energy and fuels, enzyme technology, waste utilization, biodiversity conservation, etc. (Fig. 1).

Biotechnology has great impact in areas like Environment, Bioinformatics, Genomics Proteomics and Human Genome Project (HGP).


Table of Contents

1 Unit 1. The Foundations of Biotechnology

  • Chapter 1. The Study of Life
  • Chapter 2. The Building Blocks of Life
  • Chapter 3. What is Biotechnology?
  • Chapter 4. Biotechnician Tools: Measurements & Uncertainty
  • Chapter 5. Biotechnician Tools: Preparing Solutions
  • Chapter 6. Biotechnician Tools: Basic Laboratory Equipment

2 Unit 2. Introduction to Biomanufacturing

  • Chapter 7. Cell Structure and Function
  • Chapter 8. Microbes
  • Chapter 9. Microbial Techniques
  • Chapter 10. Microbial Growth
  • Chapter 11. Control of Microbial Growth

3 Unit 3. Molecular Biotechnology

  • Chapter 12. Nucleic Acid Structure & Function
  • Chapter 13. Protein Structure and Function
  • Chapter 14. Laboratory Techniques: Nucleic Acids and Proteins
  • Chapter 15. Viruses, Vaccines, and the Immune System
  • Chapter 16. Immunochemistry

Role of Biotechnology in Molecular Diagnosis

In order to treat the disease effectively, it is important to diagnose the disease and understand it at the early stage. If we go through the conventional diagnosis method, we are not able to diagnose the disease early. But with the help of biotechnological techniques like Polymerase Chain Reaction (PCR), Recombinant DNA technology and Enzyme Linked Immuno – Sorbent Assay (ELISA) are some of the techniques that help in early diagnosis of diseases. ELISA is based on the interaction of antigen – antibody.


Environmental Biotechnology: Meaning, Applications and Other Details

Environmental biotechnology in particular is the application of processes for the protection and restoration of the quality of the environment.

Environmental biotechnology can be used to detect, prevent and remediate the emission of pollutants into the environment in a number of ways.

Solid, liquid and gaseous wastes can be modified, either by recycling to make new products, or by purifying so that the end product is less harmful to the environment. Replacing chemical materials and processes with biological technologies can reduce environmental damage.

In this way environmental biotechnology can make a significant contribution to sustainable development. Environmental Biotechnology is one of today’s fastest growing and most practically useful scientific fields. Research into the genetics, biochemistry and physiology of exploitable microorganisms is rapidly being translated into commercially available technologies for reversing and preventing further deterioration of the earth’s environment.

Objectives of Environmental Biotechnology (According to Agenda 21):

The aim of environmental biotechnology is to prevent, arrest and reverse environmental degradation through the appropriate use of biotechnology in combination with other technologies, while supporting safety procedures as a primary component of the programme.

Specific Objectives are:

1. To adopt production processes that make optimal use of natural resources, by recycling biomass, recovering energy and minimizing waste generation.

2. To promote the use of biotechnological techniques with emphasis on bioremediation of land and water, waste treatment, soil conservation, reforestation, afforestation and land rehabilitation.

3. To apply biotechnological processes and their products to protect environmental integrity with a view to long-term ecological security.

Use of biotechnology to treat pollution problems is not a new idea. Communities have depended on complex populations of naturally occurring microbes for sewage treatment for over a century. Every living organism—animals, plants, bacteria and so forth—ingests nutrients to live and produces a waste as a by-product. Different organisms need different types of nutrients.

Certain bacteria thrive on the chemical components of waste products. Some microorganisms feed on materials toxic to others. Research related environmental biotechnology is vital in developing effective solutions for mitigating, preventing and reversing environmental damage with the help of these living forms. Growing concern about public health and the deteriorating quality of the environment has prompted the development of a range of new, rapid analytical devices for the detection of hazardous compounds in air, water and land. Recombinant DNA technology has provided the possibilities for the prevention of pollution and holds a promise for a further development of bioremediation.

Applications of Environmental Biotechnology:

Environmental protection is an integral component of sustainable development. The environment is threatened every day by the activities of man. With the continued increase in the use of chemicals, energy and non-renewable resources by an expanding global population, associated environmental problems are also increasing. Despite escalating efforts to prevent waste accumulation and to promote recycling, the amount of environmental damage caused by over-consumption, the quantities of waste generated and the degree of unsustainable land use appear likely to continue growing.

The remedy can be achieved, to some extent, by the application of environmental biotechnology techniques, which use living organisms in hazardous waste treatment and pollution control. Environmental biotechnology includes a broad range of applications such as bioremediation, prevention, detection and monitoring, genetic engineering for sustainable development and better quality of living.

Bioremediation refers to the productive use of microorganisms to remove or detoxify pollutants, usually as contaminants of soils, water or sediments that otherwise intimidate human health. Bio treatment, bio reclamation and bio restoration are the other terminologies for bioremediation. Bioremediation is not a new practice. Microorganisms have been used for many years to remove organic matter and toxic chemicals from domestic and manufacturing waste discharge.

However, the focus in environmental biotechnology for fighting different pollution is on bioremediation. The vast majority of bioremediation applications use naturally occurring microorganisms to identify and filter toxic waste before it is introduced into the environment or to clean up existing pollution problems.

Some more advanced systems using genetically modified microorganisms are being tested in waste treatment and pollution control to remove difficult-to-degrade materials. Bioremediation can be performed in situ or in specialized reactors (ex situ). Bioremediation by microorganisms need appropriate environment for the clean up of the polluted site.

Addition of nutrients, terminal electron acceptors (O2/NO2), temperature, moisture to promote the growth of a particular organism may be required for the microbial activity in the polluted site. Bioremediation operations may be made either on-site or off-site, in situ or ex situ. Bioremediation has a vast potential to clean up water and soil contaminated by a variety of hazardous pollutants, domestic wastes, radioactive wastes etc.

Biological cleaning procedures make use of the fact that most organic chemicals are subjected to enzymatic attack of living organisms. The most common approach is the use of enzymes as substitute chemical catalysts. Significant reduction or complete elimination of harsh chemicals may be achieved as is observed in leather, textile processing and pulp and paper industry.

Only 1-2g of hemicellulose is substituted for 10-15 kg of chlorine to treat 1 tonne of pulp, thereby significantly reducing the chlorinated organic effluent. Environmental protection and remediation presently combine biotechnological, chemical, physical and engineering methods.

The relative importance of biotechnology is increasing as scientific knowledge and methods improve. Its lower requirements for energy and chemicals, combined with lower production of minor wastes, make it an increasingly desirable alternative to more traditional chemical and physical methods of remediation. Applications of bioremediation for maintenance of environment are several. In this chapter a few are dealt with as handling of waste water and industrial effluents, soil and land treatment, air and waste gases management.

Waste Water and Industrial Effluents:

Water pollution is a serious problem in many countries of the world. Rapid industrialisation and urbanization have generated large quantities of waste water that resulted in deterioration of surface water resources and ground water reserves. Biological, organic and inorganic pollutants contaminate the water bodies.

In many cases, these sources have been rendered unsafe for human consumption as well as for other activities such as irrigation and industrial needs. This illustrates that degraded water quality can, in effect, contribute to water scarcity as it limits its availability for both human use and the ecosystem. Treatment of the waste water before disposal is of urgent concern worldwide.

In sewage treatment plants microorganisms are used to remove the more common pollutants from waste water before it is discharged into rivers or the sea. Increasing industrial and agricultural pollution has led to a greater need for processes that remove specific pollutants such as nitrogen and phosphorus compounds, heavy metals and chlorinated compounds.

Methods include aerobic, anaerobic and physico-chemical processes in fixed-bed filters and in bioreactors in which the materials and microbes are held in suspension. Sewage and other waste waters would, if left untreated, undergo self-purification but the process requires long exposure periods. To speed up this process bioremediation measures are used.

However, Five Key Stages are Recognized in Wastewater Treatment:

a) Preliminary treatment – grit, heavy metals and floating debris are removed.

b) Primary treatment – suspended matters are removed.

c) Secondary treatment – bio-oxidize organic materials by activities of aerobic and anaerobic microorganisms.

d) Tertiary treatment – specific pollutants are removed (ammonia and phosphate).

e) Sludge treatment – solids are removed (final stage).

Aerobic Biological Treatment:

Trickling filters, rotating biological contactors or contact beds, usually consist of an inert material (rocks/ash/ wood/ metal) on which the microorganisms grow in the form of a complex biofilm. These have been used for more than 70 years for sewage and waste water treatment. In these processes the degradable organic matter is oxidized by the microorganisms to CO2 that can be vented to the atmosphere.

Activated Sludge Process:

This process is used for treatment and removal of dissolved and biodegradable wastes, such as organic chemicals, petroleum refining wastes textile wastes and municipal sewage. The microorganisms in activated sludge generally are composed of 70-90% organic and 10-30% inorganic matters.

The microorganisms found in this sludge are usually bacteria, fungi, protozoa and rotifers. Petroleum hydrocarbons are degraded by species of bacteria (Acinetobacter, Mycobacteria, Pseudomonas etc.), yeasts, Cladosporium and Scolecobasidium. Pesticides (aldrin, dieldrin, parathion, malathion) are detoxified by fungus Xylaria xylestrix. Pseudomonas (a predominant soil microrganism) can detoxify organic compounds like hydrocarbons, phenols, organophosphates, polychlorinated biphenyls and polycyclic aromatics.

Utilisation of immobilized cyanobacterium Phormidium laminosum in batch and continuous flow bioreactors for the removal of nitrate, nitrite and phosphate from water has been reported by Garbisu et al. (2003). Blanco et al. (2003) showed the biosorption of heavy metal by Phormidium laminosum immobilised in micro-porous polymeric matrices. Photo-bioreactors are currently used to grow algae and cyanobacteria under closely controlled environmental conditions, with a view to making high-value products (such as beta-carotene and gamma-linoleic acid), designing efficient effluent treatment processes, and providing new energy sources.

The costs of wastewater treatment can be reduced by the conversion of wastes into useful products. Sulphur metabolizing bacteria can remove heavy metals and sulphur compounds from waste streams of the galvanization industry and reused. Most anaerobic wastewater treatment systems produce useful biogas.

In some cases, the by-products of the pollution-fighting microorganisms are themselves useful. Methane, for example, can be derived from a form of bacteria that degrades sulphur liquor, a waste product of paper manufacturing.

Soil and Land Treatment:

As the human population grows, its demand for food from crops increases, making soil conservation crucial. Deforestation, over-development, and pollution from man-made chemicals are just a few of the consequences of human activity and carelessness. The increasing amounts of fertilizers and other agricultural chemicals applied to soils and industrial and domestic waste-disposal practices, led to the increasing concern of soil pollution. Pollution in soil is caused by persistent toxic compounds, chemicals, salts, radioactive materials, or disease-causing agents, which have adverse effects on plant growth and animal health.

Many species of fungi can be used for soil bioremediation. Lipomyces sp. can degrade herbicide paraquat. Rhodotorula sp. can convert benzaldehyde to benzyl alcohol. Candida sp. degrades formaldehyde in the soil. Aspergillus niger and Chaetomium cupreum are used to degrade tannins (found in tannery effluents) in the soil thereby helping in plant growth.

Phanerochaete chrysosporium has been used in bioremediation of soils polluted with different chemical compounds, usually recalcitrant and regarded as environmental pollutants. Decrease of PCP (Pentachlorophenol) between 88-91% within six weeks was observed in presence of Phanerochaete chrysosporium.

Bioremediation of contaminated soil has been used as a safe, reliable, cost-effective and environment friendly method for degradation of various pollutants. This can be effected in a number of ways, either in situ or by mechanically removing the soil for treatment elsewhere.

In situ treatments include adding nutrient solutions, introducing microorganisms and ventilation. Ex situ treatment involves excavating the soil and treating it above ground, either as compost, in soil banks, or in specialised slurry bioreactors. Bioremediation of land is often cheaper than physical methods and its products are largely harmless.

During biological treatment soil microorganisms convert organic pollutants to CO2, water and biomass. Degradation can take place under aerobic as well as under anaerobic conditions. Soil bioremediation can also be accomplished with the help of bioreactors. Degradation can take place under aerobic as well as under anaerobic conditions. Soil bioremediation can also be accomplished with the help of bioreactors. Liquids, vapours, or solids in a slurry phase are treated in a reactor. Microbes can be of natural origin, cultivated or even genetically engineered.

Research in the field of environmental biotechnology has made it possible to treat soil contaminated with mineral oils. Solid-phase technologies are used for petroleum-contaminated soils that are excavated, placed in a containment system through which water and nutrients percolate. Biological degradation of oils has proved commercially viable both on large and small scales, in situ and ex situ.

In situ soil bioremediation involve the stimulation of indigenous microbial populations (e.g. by adding nutrients or aeration). In this process the environmental conditions for the biological degradation of organic pollutants are optimized as far as possible. Oxygen has to be supplied by artificial aeration or by adding electron acceptors such as nitrates or oxygen releasing compounds. Ozone dissolved in water and H2O2 are sometimes used which degrade the organic contaminants.

With the onset of human civilization, the air is one of the first and most polluted components of the atmosphere. Most air pollution comes from one human activity: burning fossil fuels—natural gas, coal, and oil—to power industrial processes and motor vehicles. When fuels are incompletely burned, various chemicals called volatile organic chemicals (VOCs) also enter the air. Pollutants also come from other sources.

For instance, decomposing garbage in landfills and solid waste disposal sites emits methane gas, and many household products give off VOCs. Expanding industrial activities have added more contaminants in the air.

The concept of biological air treatment at first seemed impossible. With the development of biological waste gas purification technology using bioreactors—which includes bio filters, bio trickling filters, bio scrubbers and membrane bioreactors—this problem is taken care of. The mode of operation of all these reactors is similar.

Air containing volatile compounds is passed through the bioreactors, where the volatile compounds are transferred from the gas phase into the liquid phase. Microbial community (mixture of different bacteria, fungi and protozoa) grow in this liquid phase and remove the compounds acquired from the air.

In the bio filters, the air is passed through a bed packed with organic materials that supplies the necessary nutrients for the growth of the microorganisms. This medium is kept damp by maintaining the humidity of the incoming air. Biological off-gas treatment is generally based on the absorption of the VOC in the waste gases into the aqueous phase followed by direct oxidation by a wide range of voracious bacteria, which include Nocardia sp. and Xanthomonas sp.

Sustainable development and quality living depends upon the rational, eco-friendly use of natural resources with economic growth. To comply with this trend, industrial development has to change to sustainable style from degradative type and for such a purpose cleaner technologies have to be adopted.

According to United Nations Environment Programme (1996) ‘the continuous application of an integrated preventive environmental strategy to processes, products and services to increase eco-efficiency and reduce risks to humans and the environment’ defines the eco-friendly concept. The application of preventive and clean concept can only be achieved by the 5R policies (Olguin et al, 2003).

Five Environmental Buzzwords are the 5Rs for Efficient Use of Energy and Better Control of Waste, Which Might Help in Sustainable Development and Quality Living:

1. Reduce (Reduction of waste)

2. Reuse (Efficient use of water, energy)

3. Recycle (Recycling of wastes)

4. Replace (Replacement of toxic/hazardous raw materials for more environment- friendly inputs)

5. Recover (useful non-toxic fractions from wastes)

Innovation and adoption of clean technologies is the target of research and development worldwide. Industrial companies are developing processes with reduced environmental impact responding to the international call for the development of a sustainable society. There is a pervading trend towards less harmful products and processes away from “end-of-pipe” treatment of waste streams. Environmental biotechnology, with its appropriate technologies, is suitable to contribute to this trend.

Enzymes are widely employed in industries for many years. Enzymes, non-toxic and biodegradable, are biological catalysts that are highly competent and have numerous advantages over non-biological catalysts. The use of enzyme by man, both directly and indirectly, have been for thousands of years.

In the recent years enzymes have played important roles in the production of drugs, fine chemicals, amino acids, antibiotics and steroids. Industrial processes can be made eco-friendly by the use of enzymes. Enzyme application in the textile, leather, food, pulp and paper industries help in significant reduction or complete elimination of severe chemicals and are also more economic in energy and resource consumption.

Biotechnological methods can produce food materials with improved nutritional value, functional characteristics, shelf stability. Plant cells grown in fermenters can produce flavours such as vanilla, reducing the need for extracting the compounds from vanilla beans. Food processing has benefited from biotechnologically produced chymosin which is used in cheese manufacture alpha-amylase, which is used in production of high-fructose corn syrup and dry beer and lactase, which is added to milk to reduce the lactose content for persons with lactose intolerance.

Genetically engineered enzymes are easier to produce than enzymes isolated from original sources and are favoured over chemically synthesized substances because they do not create by-products or off-flavours in foods.

Environmental Detection and Monitoring:

A wide range of biological methods are in use to detect pollution and for the continuous monitoring of pollutants. The techniques of biotechnology have novel methods for diagnosing environmental problems and assessing normal environmental conditions so that human beings can be better- informed of the surroundings. Applications of these methods are cheaper, faster and also portable.

Rather than gathering soil samples and sending them to a laboratory for analysis, scientists can measure the level of contamination on site and know the results immediately. Biological detection methods using biosensors and immunoassays have been developed and are now in the market. Microbes are used in biosensors contamination of metals or pollutants. Saccharomyces cerevisiae (yeast) is used to detect cyanide in river water while Selenastrum capricornatum (green alga) is used for heavy metal detection. Immunoassays use labelled antibodies (complex proteins produced in biological response to specific agents) and enzymes to measure pollutant levels. If a pollutant is present, the antibody attaches itself to it making it detectable either through colour change, fluorescence or radioactivity.

A biosensor is an analytical device that converts a biological response into an physical, chemical or electrical signal. The development of biosensors involves integration of a specific and sensitive biologically derived sensing elements (immobilized cells, enzymes or antibodies) are integrated with physico-chemical transducers (either electrochemical or optical). Immobilised on a substrate, their properties change in response to some environmental effect in a way that is electronically or optically detectable.

It is then possible to make quantitative measurements of pollutants with extreme precision or to very high sensitivities. The biological response of the biosensor is determined by the bio catalytic membrane, which accomplishes the conversion of reactant to product. Immobilised enzymes possess a number of advantageous features which makes them particularly applicable for use in such systems.

They may be re-used, which ensures that the same catalytic activity is present for a series of analyses. Biosensors are powerful tools, which rely on biochemical reactions to detect specific substances, which have brought benefits to a wide range of sectors, including the manufacturing, engineering, chemical, water, food and beverage industries. They are able to detect even small amounts of their particular target chemicals, quickly, easily and accurately.

For this character of biosensors they have been ardently adopted for a variety of process monitoring applications, principally in respect to pollution assessment and control. Biosensors for detection of carbohydrates, organic acids, glucosinolates, aromatic hydrocarbons, pesticides, pathogenic bacteria and others have already been developed.

The biosensors can be designed to be very selective, or sensitive to a broad range of compounds. For example, a wide range of herbicides can be detected in river water using algal-based biosensors the stresses inflicted on the organisms being measured as changes in the optical properties of the plant’s chlorophyll. Biosensors are of different types such as calorimetric biosensors, immunosensors, optical biosensors, BOD biosensors, gas biosensors.

The remarkable ability of microbes to break down chemicals is proving useful, not only in pollution remediation but also in pollutant detection. A group of scientists at Los Alamos National Laboratory work with bacteria that degrade a class of organic chemicals called phenols. When the bacteria ingest phenolic compounds, the phenols attach to a receptor.

The phenol-receptor complex then binds to DNA, activating the genes involved in degrading phenol. The Los Alamos scientists added a reporter gene that, when triggered by a phenol-receptor complex, produces an easily detectable protein, thus indicating the presence of phenolic compounds in the environment. Biosensors employing acetylcholine esterase can be used for the detection of organophosphorus compounds in water.

Biotechnology, which is expected to make a great contribution to the welfare of mankind, is an important technology that should be steadily developed. The application of DNA technology, among the different kinds of biotechnology, has the possibility to create new gene combinations that have not previously existed in nature.

Since its beginning, genetic engineering has claimed to be able to construct tailor-made microorganisms with improved degrading capabilities for toxic substances. With the development of GEM (genetically engineered microorganism) and their possible utilization in the treatment of contaminated soil and water, stability of plasmids is extremely desirable. Plasmids are circular strands of DNA that replicates as separate entities independent of the host chromosome. Plasmids can range in size from those that carry only a couple of genes to ones carrying much greater numbers. Small plasmids may be present as multiple copies. Exchange of genetic information via plasmids is achieved by the process of conjugation.

The use of restriction enzymes has enabled the isolation of particular DNA fragments that can be transferred to another organism lacking the same. Genes which code for metabolism of environmental pollutants such as PCB’s and other xenobiotic compounds are frequently, although not always, located on plasmids.

The possibility of genetic transfer in non-biodegradative microbes has opened a new outlook of bio treatment of wastes. The recombinant DNA has the ability to multiply and may also confer the specific derivative capacity to detoxify environmental contaminants.

Gene transfer among microbial communities has improved the derivative capacity in vitro. The first patent for a genetically modified organism (GMO) or GEM, filed in the USA by Professor A. M. Chakrabarty was for a bacterium Pseudomonas putida with hydrocarbon degrading abilities. Subsequent reports have noted the role of plasmids in degradation of alkanes, naphthalene, toluene, m— and p— xylenes.

Given the overwhelming diversity of species, biomolecules and metabolic pathways on this planet, genetic engineering can, in principle, be a very powerful tool in creating environmentally friendlier alternatives for products and processes that presently pollute the environment or exhaust its non-renewable resources.

Nowadays organisms can be supplemented with additional genetic properties for the biodegradation of specific pollutants if naturally occurring organisms are not able to do that job properly or not quickly enough. By combining different metabolic abilities in the same microorganism blockage in environmental cleanup may be circumvented.

In the USA some genetically modified bacteria have been approved for bioremediation purposes but large scale applications have not yet been reported. In Europe only controlled field tests have been authorized. Just as light, heat, and moisture can degrade many materials, biotechnology relies on naturally occurring, living bacteria to perform a similar function but the action is faster.

Some bacteria naturally feed on chemicals and other wastes, including some hazardous materials. They consume those materials, digest them, and excrete harmless substances in their place. Bioremediation uses natural as well as recombinant microorganisms to break down toxic and hazardous substances already present in the environment. Bio treatment can be used to detoxify waste streams at the source before they contaminate the environment – rather than at the point of disposal. This approach involves carefully selecting organisms, known as biocatalysts, which are enzymes that degrade specific compounds and accelerate the degradation process.

However, the application of GMOs/GEMs, in the environment for bioremediation may create problems in the ecosystem. These exclusively designed organisms do not get a chance to experience the various fluctuating environmental conditions which is faced by naturally occurring organisms during the evolutionary processes spaning millions of years.

As a result, the latter are well adapted to the changing environmental conditions such as changes in temperature, substrate or waste concentrations. But when exposed to the contaminated site, GMOs show a higher viability than naturally occurring bacteria, due to their tailored enzymatic equipment.

There are concerns about the negative effect of these GMOs on the complex and delicate microbial ecosystems by competition or the exchange of genetic material in the soils to which they are applied. Even more worrisome is their potential effect outside the treatment area. While recombinant strains may appear harmless in the laboratory, it is virtually impossible to assess their impact in the field.

Biotechnical methods are now used to produce many proteins for pharmaceutical and other specialized purposes. Human insulin, the first genetically engineered product to be produced commercially (1982) is made by nonvirulent strain of Escherichia coli bacteria, by introduction of a copy of the gene for human insulin.

When the gene is “amplified” the bacterial cells produce large quantities of human insulin that are purified and used to treat diabetes in human beings. A number of other genetically engineered products have been approved since then, including human growth hormone, alpha interferon, recombinant erythropoietin and tissue plasminogen activator.

Biotechnology techniques are being applied to plants to produce plant materials with improved composition, functional characteristics. Among the first commercially available whole food products was the slow-ripening tomato, the gene for polygalacturonase, the enzyme responsible for softening, is turned off in this tomato. Plants that are resistant to disease, pests, environmental conditions, or selected herbicides or pesticides are also being developed.

In 1995, the Environmental Protection Agency (EPA) gave clearance for development of transgenic corn seed, cotton seed, and seed potatoes that contain the genetic material to resist certain insects. The advantage of such products is that they allow the use of less toxic and more environmentally friendly herbicides and pesticides.

The first approved application of biotechnology to animal production was the use of recombinant bovine somatotropin (BST) in dairy cows. Bovine somatotropin, a protein hormone found naturally in cows, is necessary for milk production. When the recombinant BST is administered to dairy cows under ideal management conditions, milk production has been shown to increase by 10% to 25%.

Other uses of biotechnology in animal production include development of vaccines to protect animals from disease, production of several calves from one embryo (cloning), artificial insemination, improvement of growth rate and/or feed efficiency, and rapid disease detection.

Natural bio-pesticides are another development of biotechnology that help farmers reduce chemical use. They degrade rapidly, leave no residues, and are toxic only to target insects. Bacillus thuringiensis (B.t.), produces a protein that is naturally toxic to certain insects. Scientists have extracted the B.t. gene that expresses the insecticide and inserted it into common bacteria that can be grown in large quantities by the same fermentation techniques used to produce such everyday products as beer and antibiotics. Spread on cotton and other crops, these harmless bacteria control insects naturally.

Moreover, a wide range of crop plants have been genetically engineered to express the cry genes (found in B. t.) in their tissues, so the insects get killed as they feed on these crops. Pollution control by genetic engineering is likely to work best when pollutants are a known mixture of relatively concentrated organic compounds that are related to each other in structure, where conventional alternative organic nutrients are absent, and when there is no competition from indigenous microorganisms.

The spectacular metabolic versatility of bacteria and fungi is exploited in the area environmental bioremediation as in sewage and waste water treatment, degradation of xenobiotics and metal abatement. Genetic manipulation offers a way of engineering microorganisms to deal with a pollutant, or a family of closely related pollutants, that may be present in the waste stream from an industrial process.

The simplest approach is to extend the degradative capabilities of existing metabolic pathways within an organism either by introducing additional enzymes from other organisms or by modifying the specificity or catalytic mechanisms of enzymes already present.

A treatment plant at the Homestake Mine in Lead, South Dakota, purifies 4 million gallons of cyanide-containing wastewater a day by completely converting cyanide to nitrate. Pseudomonas sp. convert cyanide and thiocyanate to ammonia and bicarbonate and the nitrifying bacteria Nitrosomonas and Nitrobacter cooperate in converting ammonia to nitrate. Recombinant DNA technology has had amazing repercussion in the last few years in environmental protection and also in other fields for better quality of living.

Different Areas of Environmental Biotechnology:

Environmental Biotechnology and Metagenomics:

Environmental Biotechnology is Divided into Different Areas:

(i) Direct studies of the environment,

(ii) Research with a focus on applications to the environment and

(iii) Research that applies information from the environment to other venues.

Here, a brief account of a particular aspect of direct analysis of environment is given.

In addition to DNA inside living organisms, there is much free DNA in the environment that might also be a source of new genes. The field of environmental biotechnology has revolutionized the study of the life-forms which have not been studied earlier and DNA.

This approach is direct analyses of the environment and the natural biochemical processes that are present. A significant study in this aspect is metagenomics. Metagenomics is the study of the genomes of whole communities of microscopic life forms and it deals with a mixture of DNA from multiple organisms, viruses, viroids, plasmids and free DNA.

In other words, metagenomics, the genomic analysis of a population of microorganisms, is the method to gain access to the physiology and genetics of uncultured organisms.

Using metagenomics, researchers investigate, catalogue the current microbial diversity. New proteins, enzymes and biochemical pathways are identified. The knowledge garnered from metagenomics has the potential to affect the ways we use the environment. Metagenomic analyses involves isolating DNA from an environmental sample, cloning the DNA into a suitable vector, transforming the clones into a host bacterium and screening the resultant transformants.

The clones can be screened for phylogenetic markers such as 16S rRNA and rec A or for other conserved genes by hybridization or multiplex PCR or for expression of specific traits such as enzyme activity or antibiotic production or they can be sequenced randomly.

One very important method for metagenomic study is stable isotope probing (SIP). An environmental sample of water or soil is first mixed with a precursor such as methanol, phenol, carbonate or ammonia that has been labeled with a stable isotope such as 15 N, 13 C or 18 O. If the organisms in the sample metabolize the precursor substrate, the stable isotope is incorporated into their genome.

When the DNA from the sample is isolated and separated by centrifugation, the genomes that incorporated the labeled substrate will be heavier and can be separated from the other DNA in the sample. The heavier DNA will migrate further in a cesium chloride gradient during centrifugation. The DNA can be used directly or cloned into vectors to make a metagenomic library. This technique is useful to find new organisms that can degrade contaminants such as phenol.

Microorganisms are crucial participants in cleaning up a large variety of hazardous substances/chemicals by transforming them into forms that are harmless to people and environment. One very important example is given here. Gasoline is leaked into soil in every gas station in United States.

There is every possibility that gasoline will be mixed with ground water which is the prime source of drinking water. However, the dormant members of the soil microbial community are triggered to become active and degrade the harmful chemicals in gasoline.

Since gasoline is composed of hundreds of chemicals it takes a variety of microbes working together to degrade them all. When some bacteria cause a depletion of O2 in ground water near a gasoline spill, other types of bacteria that can use nitrate for energy begin biodegrading the gasoline. Bacteria that use iron, manganese and sulfate follow.

All these microbial communities work together in a pattern to transform leaking gasoline into CO2 and water. Metagenomic analysis may help us identify the particular community member and function needed to achieve the full chemical transformation that will keep our planet livable.


Medicinal Biotechnology

It is easy to see how biotechnology can be used for medicinal purposes. Knowledge of the genetic makeup of our species, the genetic basis of heritable diseases, and the invention of technology to manipulate and fix mutant genes provides methods to treat the disease.

Genetic Diagnosis and Gene Therapy

Figure 1. Gene therapy using an adenovirus vector can be used to cure certain genetic diseases in which a person has a defective gene. (credit: NIH)

The process of testing for suspected genetic defects before administering treatment is called genetic diagnosis by genetic testing. Depending on the inheritance patterns of a disease-causing gene, family members are advised to undergo genetic testing. For example, women diagnosed with breast cancer are usually advised to have a biopsy so that the medical team can determine the genetic basis of cancer development. Treatment plans are based on the findings of genetic tests that determine the type of cancer. If the cancer is caused by inherited gene mutations, other female relatives are also advised to undergo genetic testing and periodic screening for breast cancer. Genetic testing is also offered for fetuses (or embryos with in vitro fertilization) to determine the presence or absence of disease-causing genes in families with specific debilitating diseases.

Gene therapy is a genetic engineering technique used to cure disease. In its simplest form, it involves the introduction of a good gene at a random location in the genome to aid the cure of a disease that is caused by a mutated gene. The good gene is usually introduced into diseased cells as part of a vector transmitted by a virus that can infect the host cell and deliver the foreign DNA (Figure 1). More advanced forms of gene therapy try to correct the mutation at the original site in the genome, such as is the case with treatment of severe combined immunodeficiency (SCID).

Production of Vaccines, Antibiotics, and Hormones

Traditional vaccination strategies use weakened or inactive forms of microorganisms to mount the initial immune response. Modern techniques use the genes of microorganisms cloned into vectors to mass produce the desired antigen. The antigen is then introduced into the body to stimulate the primary immune response and trigger immune memory. Genes cloned from the influenza virus have been used to combat the constantly changing strains of this virus.

Antibiotics are a biotechnological product. They are naturally produced by microorganisms, such as fungi, to attain an advantage over bacterial populations. Antibiotics are produced on a large scale by cultivating and manipulating fungal cells.

Recombinant DNA technology was used to produce large-scale quantities of human insulin in E. coli as early as 1978. Previously, it was only possible to treat diabetes with pig insulin, which caused allergic reactions in humans because of differences in the gene product. In addition, human growth hormone (HGH) is used to treat growth disorders in children. The HGH gene was cloned from a cDNA library and inserted into E. coli cells by cloning it into a bacterial vector.

In Summary: Medicinal Biotechnology

Transgenic organisms possess DNA from a different species, usually generated by molecular cloning techniques. Vaccines, antibiotics, and hormones are examples of products obtained by recombinant DNA technology. Transgenic plants are usually created to improve characteristics of crop plants.


Environmental Biotechnology for sustainable future

  • Author : Ranbir Chander Sobti
  • Publisher : Springer
  • Release Date : 2018-09-10
  • Genre: Technology & Engineering
  • Pages :
  • ISBN 10 : 9811072833

Environmental sustainability is one of the biggest issues faced by the mankind. Rapid & rampant industrialization has put great pressure on the natural resources. To make our planet a sustainable ecosystem, habitable for future generations & provide equal opportunity for all the living creatures we not only need to make corrections but also remediate the polluted natural resources. The low-input biotechnological techniques involving microbes and plants can provide the solution for resurrecting the ecosystems. Bioremediation and biodegradation can be used to improve the conditions of polluted soil and water bodies. Green energy involving biofuels have to replace the fossil fuels to combat pollution & global warming. Biological alternatives (bioinoculants) have to replace harmful chemicals for maintaining sustainability of agro-ecosystems. The book will cover the latest developments in environmental biotech so as to use in clearing and maintaining the ecosystems for sustainable future.


Section Summary

Genome mapping is similar to solving a big, complicated puzzle with pieces of information coming from laboratories all over the world. Genetic maps provide an outline for the location of genes within a genome, and they estimate the distance between genes and genetic markers on the basis of the recombination frequency during meiosis. Physical maps provide detailed information about the physical distance between the genes. The most detailed information is available through sequence mapping. Information from all mapping and sequencing sources is combined to study an entire genome.

Whole genome sequencing is the latest available resource to treat genetic diseases. Some doctors are using whole genome sequencing to save lives. Genomics has many industrial applications, including biofuel development, agriculture, pharmaceuticals, and pollution control.

Imagination is the only barrier to the applicability of genomics. Genomics is being applied to most fields of biology it can be used for personalized medicine, prediction of disease risks at an individual level, the study of drug interactions before the conduction of clinical trials, and the study of microorganisms in the environment as opposed to the laboratory. It is also being applied to the generation of new biofuels, genealogical assessment using mitochondria, advances in forensic science, and improvements in agriculture.

Proteomics is the study of the entire set of proteins expressed by a given type of cell under certain environmental conditions. In a multicellular organism, different cell types will have different proteomes, and these will vary with changes in the environment. Unlike a genome, a proteome is dynamic and under constant flux, which makes it more complicated and more useful than the knowledge of genomes alone.

Exercises

Glossary

biomarker: an individual protein that is uniquely produced in a diseased state

genetic map: an outline of genes and their location on a chromosome that is based on recombination frequencies between markers

genomics: the study of entire genomes, including the complete set of genes, their nucleotide sequence and organization, and their interactions within a species and with other species

metagenomics: the study of the collective genomes of multiple species that grow and interact in an environmental niche

model organism: a species that is studied and used as a model to understand the biological processes in other species represented by the model organism

pharmacogenomics: the study of drug interactions with the genome or proteome also called toxicogenomics

physical map: a representation of the physical distance between genes or genetic markers

protein signature: a set of over- or under-expressed proteins characteristic of cells in a particular diseased tissue

proteomics: study of the function of proteomes

whole genome sequencing: a process that determines the nucleotide sequence of an entire genome


Watch the video: Φροντιστήρια Βαγγέλης Στεφανής Πανελλήνιες 2019 Βιολογία Κατεύθυνσης (July 2022).


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