Transgenic Bacteria: Microscopic
Factories of Biotechnology
Using recombinant DNA technology, scientists create bacteria
that can manufacture valuable substances inside industrial vats known as bioreactors.
These engineered microbes can produce large quantities of proteins, hormones
(like insulin), and vaccines when the inserted foreign gene is both replicated
and expressed efficiently.
Enhancing Agriculture Through Bacterial
Engineering
Genetically modified bacteria are now helping farmers
protect crops. For instance, bacteria that typically encourage ice formation on
leaves have been re-engineered to prevent frost damage. Others, modified to
carry genes for insect-killing toxins, can protect crops like corn by naturally
defending plant roots against pests.
Bioremediation: Nature’s Clean-Up Crew
Some bacteria are designed to clean up environmental hazards.
Scientists have enhanced the natural oil-degrading capabilities of certain
bacteria to make them more effective at clearing oil spills. Others serve as biofilters
to trap airborne pollutants or are used to remove sulfur from coal. Special
safety features, like "suicide genes," ensure these bacteria
self-destruct after completing their tasks, reducing environmental risks.
Using Bacteria to Manufacture Chemicals
Modern biotechnology allows scientists to manipulate the
genes responsible for producing industrial chemicals. One successful example
involves bacteria engineered to produce phenylalanine, a key ingredient
in NutraSweet. These modified bacteria now serve as cost-effective, reliable
producers of such compounds.
Mining and Metal Extraction with
Microbes
Major mining companies already use bacteria to extract
metals like copper, gold, and uranium from low-grade ores. Genetic engineering
is enhancing these processes, improving both efficiency and environmental
sustainability. Research is also underway to use genetically modified organisms
in the paper industry for more effective bleaching.
Transgenic Plants: From Lab to Farm
Because not all plant cells accept bacterial plasmids
naturally, scientists developed techniques to introduce foreign DNA into protoplasts—plant
cells with the wall removed. Using electric currents, they create small
openings in the plasma membrane to allow DNA entry. These modified cells can
regenerate into fully functional plants.
More than 50 genetically engineered plant varieties have
undergone field trials. Commonly modified crops include corn, soybeans,
rice, cotton, alfalfa, and potatoes, with traits like resistance to
insects, viruses, and herbicides. Some plants have even been engineered to
produce human hormones and therapeutic proteins in their seeds.
Innovations include crops like mouse-ear cress, which
can produce biodegradable plastic, and corn that generates antibodies capable
of targeting cancer cells or treating diseases like genital herpes.
Transgenic Animals: Engineering for
Health and Growth
In animals, gene insertion typically involves vortex
mixing, which allows DNA to enter egg cells through microscopic holes
created with silicon-carbide needles. This technique has produced larger
livestock such as cattle, rabbits, pigs, and fish, with enhanced growth
due to the introduction of bovine growth hormone (rbGH). These genetically
engineered animals are strictly contained to prevent ecological disruption.
Gene Pharming: Turning Animals Into
Pharmaceutical Producers
Gene pharming is the use of transgenic animals to
produce therapeutic proteins in their milk. For example, cows or goats can be
engineered to express human genes so that their milk contains drugs used to
treat infections or chronic diseases. In one case, a bull carrying the gene for
human lactoferrin passed this trait to offspring, resulting in a
sustainable source of the medication.
Interestingly, scientists have also engineered mice to
produce human growth hormone in urine, making collection and extraction
easier than from milk.
Cloning Transgenic Animals: A Leap in
Reproductive Technology
Cloning creates exact genetic copies of animals. In 1997, a
landmark achievement occurred when scientists at the Roslin Institute in
Scotland successfully cloned a sheep named Dolly using a nucleus from an
udder cell inserted into an egg with its nucleus removed. The egg was then
implanted into a surrogate mother, resulting in a healthy, cloned lamb.
Soon after, researchers in Hawaii and Japan cloned
mice and cows using nuclei from cumulus cells, demonstrating rapid advancements
in reproductive cloning. However, the cloning of humans remains legally and
ethically prohibited.
Key Takeaways for Curious Minds
- Transgenic
bacteria are widely used to produce medicines, clean up pollution, and
manufacture chemicals.
- Genetic
engineering has led to crops with improved yields, pest resistance, and
even medical capabilities.
- Transgenic
animals are being used to produce therapeutic proteins, improve food
production, and aid scientific research.
- Cloning
and gene pharming are pushing the boundaries of biotechnology, showing
both promise and ethical challenges.
- Biotechnology
continues to reshape agriculture, medicine, and industry, offering
sustainable solutions for the future.
