THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Wednesday, February 1, 1995 TAG: 9502010420
SECTION: FRONT PAGE: A1 EDITION: FINAL
SOURCE: BY JAMES SCHULTZ, STAFF WRITER
LENGTH: Medium: 91 lines
Using plant genes donated by a Virginia professor, a group of researchers working in California has announced a biotechnological breakthrough: commercially significant amounts of plastic produced from the roots, stems and leaves of a weedy plant belonging to the mustard family.
Much practical work remains before products appear on store shelves. But scientists say that growing cheap, biodegradable plastic instead of refining it expensively from oil could have a huge impact on everything from farms to garbage dumps.
``It will change the way we treat urban waste. It's also important in controlling our excess agricultural capacity,'' said Christopher Somerville, director of the Carnegie Institution's Department of Plant Biology and leader of the plastic-from-plants team. ``This stuff has higher value than food. It will have a major economic impact.''
The Carnegie researchers genetically modified the mustard plant Arabidopsis thaliana to increase 100-fold a natural plastic called polyhydroxybutyrate , or PHB. PHB is chemically similar to the kinds of petroleum-derived plastics used to make milk jugs, soda bottles, picnic utensils and a host of other household items, from containers to toys.
Any item produced from PHB will look just like its petrochemically derived cousins and be just as durable. Grown on farms and in volume for pennies a pound, PHB plastics could outprice the cheapest of petrochemical competitors.
PHB also has huge advantages environmentally. Put PHB in dirt, or in the water, and the plastic dissolves within a few years, eaten by naturally occurring soil bacteria. Compare that, say the experts, to the century or two that it takes for oil-based plastics to decompose.
``Hypothetically, you're looking at a biochemical plastic cheaper and much more environmentally friendly than a petrochemical plastic,'' said Douglas Dennis, the James Madison University biology professor whose original research and donated plant genes led to the breakthrough.
``Cost is the real attraction here. (Before this) the problem was that it's been too expensive.''
In 1989, Dennis discovered that a species of bacterium, known formally as Alcaligenes eutrophus, produced PHB. The natural plastic acts within the bacterium like fat does inside the human body, as a way to store energy.
Additional research by Dennis and others deciphered the plastic-producing genetic code. Somerville and his colleagues were thus able to transfer the PHB-generating genes inside Arabidopsis plant cells.
Biology groups around the world have been tinkering with plant genetic machinery since the early 1980s to try to produce natural plastics. Small amounts of PHB have been generated, but at great cost: $14 a pound, versus 40 cents a pound for conventional plastics.
Somerville's group is the first in the United States to produce enough PHB to make commercialization feasible. And unlike earlier efforts that stunted growth, the plastic-carrying Arabidopsis is as healthy as any of its relatives found in the wild.
If Somerville has a vision for PHB, it is to save three billion barrels of oil a year that otherwise would be refined into man-made plastics. He also hopes the PHB-producing gene can be transferred into other plants.
``If we can establish this in soybeans or some other major crop,'' Somerville said, ``we can dispense with the farm subsidy.''
For now, the discovery has been licensed to Monsanto, a multibillion-dollar food, agriculture, chemicals and pharmaceutical firm located in St. Louis. Monstanto biotechnologists are already exploring ways to alter plant genetics to make crops more resistant to pesticides and viral infections, and are researching means of improving the flavor and nutritional content of such staples as potatoes and tomatoes.
Monsanto is tight-lipped about its PHB plans. Jim Altemus, a company spokesman, says that talking about when Monsanto might roll out the natural, biodegrable plastic ``becomes an academic discussion.''
``We do an awful lot of exploratory work,'' he said. ``It would be premature to report that we are or are not commercializing biodegradable plastic or plastic from plants. It is not in our commercial pipeline now.''
However attractive environmentally or economically, any commercial plant-grown plastic will face intense scrutiny from environmental and consumer activists and government agencies like the Food and Drug Administration before it is approved for wide use, either by farmers or by manufacturers.
Will farmers one day grow environmentally friendly plastics to feed ravenous consumer appetites? Dennis and Somerville both agree that the pace of research is stepping up. For example, one group is looking at genetically modifying cotton plants to include PHB, which would create all-cotton fabrics that would also be permanent press.
``Yeah,'' said Dennis, commenting on the advance and its prospects, ``I'd say this was a big deal.'' ILLUSTRATION: Photo
A mustard plant has been genetically modified to create a natural
plastic that could replace petroleum-based plastics in a host of
household items.
by CNB