3020: Suggestions for the Listing Assignment
There are several ways this assignment could be improved:
- The first sentence should be more specific and mention bioremediation and the environment.
- There should be more space between paragraphs.
- The first sentence of each list item should be italicized.
- The list could be indented to accentuate the role of the first sentence as the topic sentence.
Scientists are now working on several new research areas:
Microorganisms are used to make some compounds less dangerous to the environment. Although coal may be our most plentiful fossil fuel, most of the nationÕs vast Eastern reserve cannot meet air-pollution standards because it emits too much sulfur when it is burned. The problem is that the aromatic compound dibenzothiothene (DBT) attaches itself to hydrocarbon molecules, producing sulfur dioxide. But the Chicago-based Institute of Gas Technology last year patented a bacterial strain that consumes the DBT (at least 90 percent, in recent lab trials) while leaving the hydrocarbon molecules intact.
Microbes are genetically engineerd to reduce the need for toxic chemicals. In 1991, the EPA approved the first genetically engineered pesticide. Called Cellcap, it incorporates a gene from one microbe that produces a toxin deadly to potato beetles and corn borers into a thick-skinned microbe that is hardier. Even then, the engineered bacteria are dead when applied to the crops.
Microorganisms are used to attack stubborn metals and radioactive waste. Microbes have been used for decades to concentrate copper and nickel in low-grade ores. Now researchers are exploiting the fact that if certain bacteria are given special foods, they excrete enzymes that break down metals and mineral. For example, researchers at the U.S. Geological Survey found that two types of bacteria turn uranium from its usual formÑone that easily dissolves in waterÑinto anotherÑone that turns to a solid that can be easily removed from water. They are now working on doing the same for other radioactive waste.
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