What Next? Polyester Plants?

THE GREAT THING ABOUT PLASTIC IS THAT IT IS cheap and it lasts forever. Unfortunately, as an inventory of any trash heap reveals, those are also its bad qualities. Scientists have spent more than a decade developing biodegradable polymers, but so far they have proved 10 times as expensive to produce as petroleum-based versions. Last week researchers at Michigan State University in East Lansing and James Madison University in Harrisonburg, Va., announced that for the first time, they have coaxed the production of a biodegradable plastic from a very inexpensive source: green plants.

In their study, which was reported in the research journal Science, Michigan's Yves Poirier and his colleagues capitalized on the environmental know-how of a select group of bacteria. In much the same way that humans store excess nutrients as fat, these germs turn sugar into the plastic molecule polyhydroxybutyrate, or PHB. They can also digest the polymer, which means it is biodegradable.

The researchers transplanted the gene for PHB from the bacteria into relatives of the mustard plant. Using energy from the sun and carbon dioxide from the air, the plants manufactured significant amounts of phb. Unfortunately, the process also stunted their growth. But eventually, Poirier expects, scientists will learn how to regulate the hybridization procedure well enough to keep these plastic producers healthy, and perhaps one day alleviate guilt over discarded bottles and wrappers.