Graphic. AgriculturesAgriculturesGraphic. Purdue University.

Spring 2001

Our new oil fields
By Steve Tally

Fortunately, plants already have methods for making and storing large amounts of compounds that help protect them from insects, disease and ultraviolet radiation in sunlight. They do this by combining (or to use the scientists' preferred term, conjugating) the molecules with other molecules to produce stable, soluble forms of the compound. These large molecules are then put into small structures called vacu-oles within the cells. The vacuoles store the compound and isolate it from the rest of the processes going on in the plant.

"The gene we've cloned produces an enzyme that is involved in conjugating these compounds in plants," Chapple says. "If you want to produce materials in plants, you first have to make sure that they can be stored in the vacuole in a safe way at a high concentration."

Because plants produce such a wide variety of natural products, Chapple says new products that aren't even being currently considered might soon be possible. "Let's think a bit more creatively," Chapple says. "In the future, we may still use polyethylene to make some plastics. But we may be able to develop plastics with such special properties that we find new uses for them. Maybe it's exactly the right compound to use in synthetic heart valves or in parts for jet aircraft, for example. It's very exciting to think about what may be possible with this research."

Stop Knocking Ethanol

Although making plastics from plants shows tremendous promise, actual products are still years away. But one petroleum substitute is already available and about to become more popular: ethanol.

In the early 1900s, automobile engines ran poorly on the gasoline of the day, knocking, sputtering and backfiring. Researchers searched for an additive to help engines run smoother, and in 1923 they found it in, tetraethyl lead, which was added to gasoline as an octane booster. But the compound introduced lead into the environment and caused widespread neurological damage in children, and in 1986 the compound was banned by the U.S. Environmental Protection Agency.

To replace leaded gasoline, petroleum companies began producing gasoline that contained an oil refinery byproduct, methyl tertiary butyl ether, or MTBE. The problem was that the lead replacement had been approved by the EPA without any research into its safety; subsequent studies found that MTBE caused cancer in animals. Because of the strong potential that the compound also causes cancer in humans, in March 2000 the EPA announced that it will begin to also phase out MTBE.

To replace these two compounds, the EPA recommended the same thing that Henry Ford had suggested in the 1920s: just add ethanol.

The knock against ethanol is that it is too expensive. But that may change thanks to research by scientists in Purdue's Laboratory of Renewable Resources Engineering, (LORRE, pronounced "Lori").



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