BIOTECHNOLOGY
Introduction
The knowledge gathered by observation and experiment ation is referred to as "Science". "Technology, on the other hand is its useful application in different fields. All progress in the modern industrial societies is based on science and technology. Technology plays an important role in areas like chemicals, glasses, plastics, fibres, paints and wax, jute, soaps, lasers, oils, etc. Biotechnology is one of the latest forms of technology. The word biotechnology is short for 'Biological Technology', which indicates the extension of technology into the biological field. Essentially, it involves the use of microbial, animal, and plant cells or enzymes to synthesise, breakdown or transform materials. It is an interdisciplinary science which requires the integration of various sciences like organic chemistry, biology, biochemistry, microbiology, chemical engineering, etc.
Biotechnology has recently gained worldwide attention. The governments of most of the developed and developing countries (including the Government of India) have allocated substantial funds for research and industrial development in this field. More than 500 companies specializing in biotechnology have sprung up worldwide in the last decade.
Applications of Biotechnology
● Insulin Production :- Insulin is an animal protein,secreted by pancreas, which controls the level of sugar in blood. It is being used as an antidiabetic drug since 1992. Till now, its production process involved the use of animal pancreas. It is a cruel and expensive method as a large number of animals have to be killed for producing a few grams of insulin. The chemical method of synthesising insulin is also very difficult and expensive. However, biotechnology has now made it possible to prepare and link a synthetic gene, responsible for synthesis of insulin, t plasmid of E. coll. After gene expression and translation of mRNA into protein, insulin is obtained. This process has already been scaled up for commercial production of insulin. This has resulted in a higher production and lower costs 80 that it can now become easily affordable by patients.
● Interferon Production :- Interferon is a term used for a family of polypeptides that have the ability to inhibit viruses. To be more particular, interferons are glycoproteins having about 150 amino acid residues per molecule. There are three types of interferons (classified on the basis of physiochemical and antigenic properties) designated as a interferon. B-interferon, and y-interferon. When there is a viral invasion, the white blood cells, particularly in the lymph tissues, trigger off mRNA synthesis for production of interferon. The interferon, in turn, activates the circulating cells, called killer cells, which attack and destroy the invading viruses. Interfon is a very powerful antiviral agent It probably causes the synthesis of several enzymes such as protein kinase and phosphodiesterase which inhibit viral replication by destroying mRNA and protein synthesis, Interfom is claimed to cure any kind of viral disease, or cancer. It is free of side effects and is used for treatment of common cold, influenza, hepatitis and herpes. It shows promise as a cure for bone cancer, skin cancer, breast cancer and leukemia. In 1980, two Americans (Gilbert and Weissmann) successfully produced interferon using biotechnological techniques by cloning the genes in Colon bacilli. Later, human leukocyte interferon (HLI) was produced by attaching a DNA sequence coding for HLI to the yeast alcohol dehydrogenase gene in a plasmid and introducing it into the cells of Saccharomyces cerevisiae (Baker's yeast). The yeast cells could synthesise about a million molecules of interferon per cell at a significantly reduced cost.
● Hormonal Production :- Hormones are compounds secreted by endocrine glands. They regulate vital body functions by interacting with target cells or organs. They are used for curing certain diseases caused by their deficiency. Synthesis of hormones is a difficult task requiring a number of synthetic steps and consequently, the costs are high. However, biothechnological techniques like recombinant DNA technology and gene cloning may be the solution to this problem. Two hormones somatostatin (hypothalamic hormone) and somatotropin (human growth hormone)-have been successfully synthesised using the recombinant DNA technology.
● Enzyme Technology :- Enzymes are complex organic molecules present in living cells. They act as catalysts for all biochemical reactions in a living cell. Without them no form of life can exist. A better understanding of biochemical processes involved has led to an increased knowledge about different onzymes and their mode c action. Enzymes are present only in the living cells, However now it has become possible to separate, isolate, and use enzymes in vitro, This capability of enzymes to catalyse reactions in and outside a cell has led to a branch of science popularly called Enzyme Technology. It is w broad term involving isolation, purification, and production of enzymes and their useful applications.
Enzymes have been used since centuries in various industrial processes like brewing, baking, fermenting, and food preservation. Enzyme technology has now acquired immense importance in production of certain materials like pharmaceuticals and agrochemicals at low cost with greater efficiency and in a purer state. Preparation of a compound in laboratory involves several synthetic steps. Quite often, it is virtually impossible to prepare a compound in the desired pure stereoisomeric form. In such cases, enzymes come to the rescue. They can act precisely and specifically, giving compounds in very high yields and in high states of (optical) purity.
Enzymes are invariably present in all the living organisms including plants. Traditionally isolation of enzymes has been done from animal and plant sources. However, now the use of enzymes isolated from microorganisms is gaining in popularity. Isolating enzyme from an animal (called mammalian enzyme) means that animal has to be killed, the particular part has to be removed by surgery and minced, and finally the enzyme to be extracted with a suitable solvent. The crude enzyme obtained by precipitation is purified by several processes and methods. The whole process is cruel, expensive, and inefficient, thus rendering it unfit for the industrial production of enzymes. Porcine pancreatic lipase, horse liver alcohol dehydrogenase, chymotrypsin, and trypsin are a few examples of commercially available enzymes. The advantages of using microbial enzymes over mammalian enzymes are:
(a) The unethical cruelty involved in production of ani mal enzymes is avoided.
(b) The microorganisms are available in abundance compared to the animals.
(c) The amount of enzymes produced in microbial cul tures is much more than that produced from animals.
(d) A range of microbial enzymes having stability over a wide range of pH and temperature are available for selection.
With the advent of gene cloning techniques, it has become possible to create microorganisms with modified genetics. Thus, new kinds of artificial enzymes can be produced.
In the industrial production of enzymes from microorganisms, a popular biotechnological method, fermentation is used wherein the microorganism is placed a fermenting substrate like starch, molasses, whey, etc. At completion of the process, the entryme is either present inside the microorganism or is secreted into the medium, which is then extracted and purified.
Fermentation Biotechnology
Fermentation technology is the technique by which useful organic compounds are prepared from less useful ones by the use of enzymes or complete living cells. The potential of microorganisms in brewing, baking and fermenting processes was realised by the people of ancient civilizations and is in use since then. The fermentation technology a at making this process more efficient, productive, and economical. All cells have the capability of converting glucose to pyruvate, whereby two ATP molecules per glucose molecule are generated in aerobic conditions. However, in absence of oxygen (anaerobic conditions). pyruvic acid is further broken down to lactic acid or ethyl alcohol. This capability of the living cell is exploited in fermentation, whereby juice of grapes and other fruits containing glucose is broken down to ethyl alcohol by the yeast cells present in the skin of the fruit.
Various organisms are used in the fermentation industry. These include yeasts, bacteria, and moulds. These microorganisms may differ greatly in size, manner of reproduction, ability to attack different substrates, etc. but they are similar in that they grow actively and produce enzymes by which they catalyse the reactions brought about by them.
In fermentation, almost everything that is a source of carbon may be used as a raw material, e.g. cellulose, sugar, starch, coal, petroleum, organic acids, etc. In general, the fermentation industry uses agricultural products as its raw materials including grain-derived substances like sugar and starch. Water is the most widely used solvent in almost all the current bio-processes. Commercial fermentation processes are nearly similar irrespective of the microorganism or the medium used and products formed. It is necessary to first test the process at laboratory level before scaling it up for industrial production. At present, a large number of products are being industrially produced by fermentation processes.
Most of the research and development in this field is centered around the production of pharmaceuticals, alcoholic beverages, organic acids, etc. Wine, beer, cheese and vinegar account for a large part of the products obtained by biotechnological processes. However, biotechnology shows promise to be useful in the production of pharma cologically active compounds, such as, vitamins, steroids, polysaccharides, etc. At present, besides ethyl alcohol. many other chemicals like n-butyl alcohol, acetone, lactic acid, sorbose, gluconic acid, itaconic acid, glycerol, 2, 3 butanediol, riboflavin and other vitamins, penicillin and other antibiotics, and various enzymes are being produced commercially by the fermentation processes.
