Biotechnology An Industry Comes of Age (1986) / Chapter Skim
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The Molecular and Microbial Products of Biotechnology
The Molecular and Microbial Products of Biotechnology
Pages 14-29
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From page 14... ...
Many of these substances are targeted at human health care: genetically engineered microorganisms can be used to produce hormones, immune regulators, vaccines, blood products, antibodies, antibiotics, and many other biologically active molecules. Other commercial sectors, such as the food additive and specialty chemicals industries, are also investigating the use of genetically engineered organisms to make new or scarce products or to make This chapter includes material from the presentations by Philip Leder and William E
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From page 15... ...
But biotechnology will also yield genetically engineered microorganisms that have more direct applications. Many of these will be in agriculture, but genetically engineered microorganisms might also be used to decompose sludge at wastewater treatment plants, to leach minerals from low-grade concentrations of ore, or to decrease the viscosity of oil deep underground to allow it to be pumped to the surface.
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From page 16... ...
This DNA is usually then spliced into the DNA of a vector, which is most often DNA from a virus; small, independently replicating loops of DNA known as plasmids, which occur in most bacteria and yeast; or genetic combinations of the two, known as cosmids. This genetically engineered vector is introduced into a host cell, which can then reproduce the DNA many
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From page 17... ...
At the same time, the bacteria can divide, creating millions of copies of the introduced DNA. This DNA can then be studied through analytical techniques, or, if a gene within the introduced DNA can be made to produce the same protein it did in its original location, the genetically engineered bacteria can be used as microbial factories to make large quantities of the protein.
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From page 18... ...
Also, the pharmaceuticals industry has considerable experience with biological processing, since about a fifth of its sales are of products manufactured wholly or in part by microorganisms. The first therapeutic agent produced through recombinant DNA techniques to be approved by the Food and Drug Administration and to be marketed was human insulin -- a protein hormone 51 amino acids long.
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From page 19... ...
Human serum albumin, a protein of 585 amino acids, is used during surgery and to treat shock, burns, and other physical trauma. Antihemophilic factors, specifically factors VIII and IX, are used by the approximately 14,000 hemophiliacs in the United States to control bleeding.
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From page 20... ...
Subunit vaccines consist of just part of a virulent organism, such as part or all of a surface protein. If less than about 50 amino acids long, subunit protein vaccines can be chemically synthesized from their constituent amino acids; proteins of these lengths and longer can also be biologically synthesized by genetically engineered microorganisms.
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From page 21... ...
Researchers are applying genetic engineering to this bacterium in an attempt to increase its productivity or give it other desirable characteristics. Tryptophan and phenylalanine are two more amino acids whose economics of production may favor biotechnology.
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From page 22... ...
The scaling-up to industrial levels of fermentation processes using genetically engineered cells involves a number of difficulties. Maintaining a homogenous mixture of nutrients and dissipating the large quantities of heat generated during fermentation are much more difficult in a full-scale industrial bioreactor than in a small benchtop flask.
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From page 23... ...
There is a pressing need in biotechnology for microorganisms better suited to fermentation technologies. For instance, the bacterium Escherichia coli, which has been widely used in genetic engineering, manufactures its products intracellularly and also produces highly toxic substances called endotoxins that must be rigorously eliminated
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From page 24... ...
It may even be possible to genetically engineer properties into microorganisms that would enhance their ability to break down certain waste substances -- not only sludge but slime, grease, and scum as well. Genetically engineered microorganisms or their products may also be able to remove heavy metals or organic pollutants, including suspected carcinogens, from drinking water and industrial wastewater.
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From page 25... ...
Cell fusion has given rise to a variety of exotic organisms, such as the hybrid plants mentioned in Chapter 3. But the most important outgrowth of cell fusion, accounting at this point for more commercial products than recombinant DNA has generated, is the production of monoclonal antibodies.
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From page 26... ...
When an effective cell line is identified, it is grown either in culture or in the body cavities of mice to produce large quantities of chemically identical, monoclonal antibodies. tion against a wide range of infectious agents and other foreign substances.
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From page 27... ...
The resulting hybrid-myeloma or hybridoma cells combined just the right qualities of each parent. They prospered in cell culture and at the same time produced virtually unlimited quantities of chemically identical or monoclonal antibodies (so named because they are produced by the cloned copies of a single hybridoma)
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From page 28... ...
"The monoclonal antibodies that have been produced thus far of great value have been derived ultimately from either mice or rats," says Paul. "Successes with cells from more distantly related animals have been rare indeed, and those results are very disappointing." In the future it may become possible, using recombinant DNA techniques, to genetically engineer cells to produce unlimited quantities of specific antibodies.
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From page 29... ...
"Although some successes have been achieved, and it would be wrong to discount those successes, this technology has not yet reached a state in which one can reliably produce human monoclonal antibodies," says Paul. "I have very little doubt that, with the very large number of individuals who have great interest in these areas, progress will be made.
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