Applications of Genetic Engineering
Genetic engineering has wide, applications in modem biotechnology. For various industrial processes,
this technique may be used in microorganisms as well as with higher organisms. The principle involved is
construction of plasmids of desired biochemical characteristics.
Plasmid technology is being hailed by many as the beginning of modem industrial microbiology. The
plasmids are tiny ringlets of DNA, apart from the chromosome, that may contain 2
250 genes. T
autonomously in the cell. The plasmids can be spliced with genes from an unrelated organism. The
genes now function to produce the protein (of unrelated organism) in the cell of host microorganism.
The following are the chief possible application
(1) Plasmids of one bacterium may be spliced with genes from other bacterium. For example it is found
that plasmids of Pseudomonas will function in other Gram
negative bacteria as Escherichia, Proteus or
Rhizohium and those staphylococcal plasmids can b
e transferred to Bacillus subtilis cells, where they will
replicate and express themselves.
(2) Since microbial cells have a much higher metabolic rate, genes of desired enzymes (of commercial
values) could be introduced into plasmid of bacteria
. For insta
nce genes of amylase synthesis could be
derived from yeasts by introducing plasmid genes for amylase production. This would enhance the
process of beer fermentations.
Similarly genes for cellulase synthesis could be incorporated into
plasmids of microbes.
The resulting large scale cellulases could be utilised for cellulose degradation.
(3) Even nitrogen fertilisers may be eliminated by incorporating plasmids, containing bacterial genes for
nitrogen fixation into the plant cells.
Plasmid technology has s
hown that products like insulin, interferon, vac-cines and human growth
hormones may be industrially possible.
By 1984, over 200
companies world over had established gene
splicing experiments, and working, on industrial applications of genetic engineering.
One company in
1980 could harvest insulin from bacteria whose plasmids had been spliced with DNA for this protein.
The DNA was from chromosome number 11 of human cells, thus product was identical with human
insulin. Marketed by Eli Lilly Corporation, the
bacterial insulin, humulin, is identical with human insulin.
In 1980, interferon was produced by genetic engineering from bacterial cells. By 1986, interferon from
engineered bacteria was being tested on rabies victims, common cold patients and cancer pati
Scientists have also inserted genes into bacteria for the production of human growth hormone. This
hormone is used to treat dwarfism. In 1986, the hormone became commercially available as protropin.
In June 1981, a vaccine for foot and mouth disease w
as developed by genetic engineering firm. There
are many other products derived from genetic engineering. Urokinase, a clot dissolving enzyme is
produced from genetically engineering bacteria. Endorphin, a pain killer is also derived from bacteria
have also been engineered to live solely on toxic wastes in the environment. A gene for hair
digesting enzyme is inserted into plasmid of bacteria. There are also attempts to engineer plants with
bacterial genes that trap N2 and convert it to a form that
could be easily taken by the plant. Yeasts are
being engineered to yield enzymes for cheese industry.