AN INTRODUCTION TO BIOTECHNOLOGY
Contrary to its name, biotechnology is not a single technology. Rather it is a group of
technologies that share two (common) characteristics -- working with living cells and their
molecules and having a wide range of practice uses that can improve our lives.
Biotechnology can be broadly defined as "using organisms or their products for commercial
purposes." As such, (traditional) biotechnology has been practices since he beginning of records
history. (It has been used to:) bake bread, brew alcoholic beverages, and breed food crops or
domestic animals (2). But recent developments in molecular biology have given biotechnology
new meaning, new prominence, and new potential. It is (modern) biotechnology that has
captured the attention of the public. Modern biotechnology can have a dramatic effect on the
world economy and society (3).
One example of modern biotechnology is genetic engineering. Genetic engineering is the
process of transferring individual genes between organisms or modifying the genes in an
organism to remove or add a desired trait or characteristic. Examples of genetic engineering are
described later in this document. Through genetic engineering, genetically modified crops or
organisms are formed. These GM crops or GMOs are used to produce biotech-derived foods. It
is this specific type of modern biotechnology, genetic engineering, that seems to generate the
most attention and concern by consumers and consumer groups. What is interesting is that
modern biotechnology is far more precise than traditional forms of biotechnology and so is
viewed by some as being far safer.)
How does modern biotechnology work?
All organisms are made up of cells that are programmed by the same basic genetic material,
called DNA (deoxyribonucleic acid). Each unit of DNA is made up of a combination of the
following nucleotides -- adenine (A), guanine (G), thymine (T), and cytosine (D) -- as well as a
sugar and a phosphate. These nucleotides pair up into strands that twist together into a spiral
structure call a "double helix." This double helix is DNA. Segments of the DNA tell individual cells how to produce specific proteins. These segments are genes. It is the presence or absence
of the specific protein that gives an organism a trait or characteristic. More than 10,000 different
genes are found in most plant and animal species. This total set of genes for an organism is
organized into chromosomes within the cell nucleus. The process by which a multicellular
organism develops from a single cell through an embryo stage into an adult is ultimately
controlled by the genetic information of the cell, as well as interaction of genes and gene
products with environmental factors. (5)
When cells reproduce, the DNA strands of the double helix separate. Because nucleotide A
always pairs with T and G always pairs with C, each DNA strand serves as a precise blueprint
for a specific protein. Except for mutations or mistakes in the replication process, a single cell is
equipped with the information to replicate into millions of identical cells. Because all organisms
are made up of the same type of genetic material (nucleotides A, T, G, and C), biotechnologists
use enzymes to cut and remove DNA segments from one organism and recombine it with DNA
in another organism. This is called recombinant DNA (rDNA) technology, and it is one of the
basic tools of modern biotechnology (6). rDNA technology is the laboratory manipulation of
DNA in which DNA, or fragments of DNA from different sources, are cut and recombined using
enzymes. This recombinant DNA is then inserted into a living organism. rDNA technology is
usually used synonymously with genetic engineering. rDNA technology allows researchers to
move genetic information between unrelated organisms to produce desired products or
characteristics or to eliminate undesirable characteristics.
Genetic engineering is the technique of removing, modifying or adding genes to a DNA
molecule in order to change the information it contains. By changing this information, genetic
engineering changes the type or amount of proteins an organism is capable of producing. Genetic
engineering is used in the production of drugs, human gene therapy, and the development of
improved plants (2). For example, an “insect protection” gene (Bt) has been inserted into several
crops - corn, cotton, and potatoes - to give farmers new tools for integrated pest management. Bt
corn is resistant to European corn borer. This inherent resistance thus reduces a farmers pesticide
use for controlling European corn borer, and in turn requires less chemicals and potentially
provides higher yielding Agricultural Biotechnology.
Although major genetic improvements have been made in crops, progress in conventional
breeding programs has been slow. In fact, most crops grown in the US produce less than their
full genetic potential. These shortfalls in yield are due to the inability of crops to tolerate or adapt
to environmental stresses, pests, and diseases. For example, some of the world's highest yields of
potatoes are in Idaho under irrigation, but in 1993 both quality and yield were severely reduced
because of cold, wet weather and widespread frost damage during June. Some of the world's best
bread wheats and malting barleys are produced in the north-central states, but in 1993 the disease
Fusarium caused an estimated $1 billion in damage.
Scientists have the ability to insert genes that give biological defense against diseases and
insects, thus reducing the need for chemical pesticides, and they will soon be able to convey
genetic traits that enable crops to better withstand harsh conditions, such as drought (8). The
International Laboratory for Tropical Agricultural Biotechnology (ILTAB) is developing
transformation techniques and applications for control of diseases caused by plant viruses in
tropical plants such as rice, cassava and tomato. In 1995, ILTAB reported the first transfer
through biotechnology of a resistance gene from a wild species of rice to a susceptible cultivated
rice variety. The transferred gene expressed resistance to Xanthomonas oryzae, a bacterium
which can destroy the crop through disease. The resistant gene was transferred into susceptible
rice varieties that are cultivated on more than 24 million hectares around the world (9).
Benefits can also be seen in the environment, where insect-protected biotech crops reduce the
need for chemical pesticide use. Insect-protected crops allow for less potential exposure of
farmers and groundwater to chemical residues, while providing farmers with season-long
control. Also by reducing the need for pest control, impacts and resources spent on the land are
less, thereby preserving the topsoil (10).
Major advances also have been made through conventional breeding and selection of livestock,
but significant gains can still be made by using biotechnology (23). Currently, farmers in the U.S
spend $17 billion dollars on animal health. Diseases such as hog cholera and pests such as
screwworm have been eradicated. Uses of biotechnology in animal production include
development of vaccines to protect animals from disease, production of several calves from one
embryo (cloning), increase of animal growth rate, and rapid disease detection (7).
Modern biotechnology has offered opportunities to produce more nutritious and better tasting
foods, higher crop yields and plants that are naturally protected from disease and insects. Modern
biotechnology allows for the transfer of only one or a few desirable genes, thereby permitting
scientists to develop crops with specific beneficial traits and reduce undesirable traits (10).
Traditional biotechnology such as cross-pollination in corn produces numerous, non-selective
changes. Genetic modifications have produced fruits that can ripen on the vine for better taste,
yet have longer shelf lives through delayed pectin degradation (7). Tomatoes and other produce
containing increased levels of certain nutrients, such as vitamin C, vitamin E, and or beta
carotene, and help protect against the risk of chronic diseases, such as some cancers and heart
disease. (10). Similarly introducing genes that increase available iron levels in rice three-fold is a
potential remedy for iron deficiency, a condition that effects more than two billion people and
causes anemia in about half that number (19). Most of the today's hard cheese products are made
with a biotech enzyme called chymosin. This is produced by genetically engineered bacteria
which is considered more purer and plentiful than it’s naturally occurring counterpart, rennet,
which is derived from calf stomach tissue.
In 1992, Monsanto Company successfully inserted a gene from a bacterium into the Russet
Burbank potato. This gene increases the starch content of the potato. Higher starch content
reduces oil absorption during frying, thereby lowering the cost of processing french fries and
chips and reducing the fat content in the finished product. This product is still awaiting final
development and approval.
Modern biotechnology offers effective techniques to address food safety concerns. Biotechnical
methods may be used to decrease the time necessary to detect foodborne pathogens, toxins, and
chemical contaminants, as well as to increase detection sensitivity. Enzymes, antibodies, and
microorganisms produced using rDNA techniques are being used to monitor food production and
processing systems for quality control (7).
Biotechnology can compress the time frame required to translate fundamental discoveries into
applications. This is done by controlling which genes are altered in an organized fashion. For
example, a known gene sequence from a corn plant can be altered to improve yield, increase
drought tolerance, and produce insect resistance (Bt) in one generation. Conventional breeding
techniques would take several years. Conventional breeding techniques would require that a field
of corn is grown and each trait is selected from individual stalks of corn. The ears of corn from
selected stalks with each desired trait (e.g, drought tolerance and yield performance) would then
be grown and combined (cross-pollinated). Their offspring (hybrid) would be further selected for
the desired result (a high performing corn with drought tolerance). With improved technology
and knowledge about agricultural organisms, processes, and ecosystems, opportunities will
emerge to produce new and improved agricultural products in an environmentally sound manner.
In summary, modern biotechnology offers opportunities to improve product quality, nutritional
content, and economic benefits. The genetic makeup of plants and animals can be modified by
either insertion of new useful genes or removal of unwanted ones. Biotechnology is changing the
way plants and animals are grown, boosting their value to growers, processors, and consumers.
Industrial biotechnology applies the techniques of modern molecular biology to improve the
efficiency and reduce the environmental impacts of industrial processes like textile, paper and
pulp, and chemical manufacturing. For example, industrial biotechnology companies develop
biocatalysts, such as enzymes, to synthesize chemicals. Enzymes are proteins produced by all
organisms. Using biotechnology, the desired enzyme can be manufactured in commercial
Commodity chemicals (e.g., polymer-grade acrylamide) and specialty chemicals can be
produced using biotech applications. Traditional chemical synthesis involves large amounts of
energy and often-undesirable products, such as HCl. Using biocatalysts, the same chemicals can
be produced more economically and more environmentally friendly. An example would be the
substitution of protease in detergents for other cleaning compounds. Detergent proteases, which
remove protein impurities, are essential components of modern detergents. They are used to
break down protein, starch, and fatty acids present on items being washed. Protease production
results in a biomass that in turn yields a useful byproduct- an organic fertilizer. Biotechnology is
also used in the textile industry for the finishing of fabrics and garments. Biotechnology also
produces biotech-derived cotton that is warmer, stronger, has improved dye uptake and retention,
enhanced absorbency, and wrinkle- and shrink-resistance.
Some agricultural crops, such as corn, can be used in place of petroleum to produce chemicals.
The crop’s sugar can be fermented to acid, which can be then used as an intermediate to produce
other chemical feedstocks for various products. It has been projected that 30% of the world’s
chemical and fuel needs could be supplied by such renewable resources in the first half of the
next century. It has been demonstrated, at test scale, that biopulping reduces the electrical energy
required for wood pulping process by 30%.
Environmental biotechnology is the used in waste treatment and pollution prevention.
Environmental biotechnology can more efficiently clean up many wastes than conventional
methods and greatly reduce our dependence on methods for land-based disposal.
Every organism ingests nutrients to live and produces by-products as a result. Different
organisms need different types of nutrients. Some bacteria thrive on the chemical components of
waste products. Environmental engineers use bioremediation, the broadest application of
environmental biotechnology, in two basic ways. They introduce nutrients to stimulate the
activity of bacteria already present in the soil at a waste site, or add new bacteria or soil. The
bacteria digest the waste at the site and turn it into harmless byproducts. After the bacteria
consume the waste materials, they die off or return to their normal population levels in the
Bioremediation, is an area of increasing interest. Through application of biotechnical methods,
enzyme bioreactors are being developed that will pre treat some industrial waste and food waste
components and allow their removal through the sewage system rather than through solid waste
disposal mechanisms. Waste can also be converted to biofuel to run generators. Microbes can be
induced to produce enzymes needed to convert plant and vegetable materials into building blocks
for biodegradable plastics (7).
In some cases, the byproducts of the pollution-fighting microorganisms are themselves useful.
For example, methane can be derived from a form of bacteria that degrades sulfur liquor, a waste
product of paper manufacturing. This methane can then be used as a fuel or in other industrial processes.
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CITED BY Kamal Singh Khadka
Msc Microbiology, TU
Assistant Professor in PU, RE-COST, PNC, NOBEL ACADEMY, LA.