5 Oktober 2004

Biodegradable plastic: Waste-disposing bug discovered

SCIENTISTS in Dublin have found a micro-organism that can change toxic waste into plastic, writes Scott Millar.

The University College Dublin team has discovered that a strain of bacteria can convert styrene, a toxic by-product of the polystyrene industry, into a biodegradable plastic.

The bacteria, Pseudomonas putida, acts as a factory and storage unit, eating the hazardous waste and accumulating the plastic inside itself. The process leaves behind none of the waste product.

Dr Kevin O’Connor, of the department of industrial microbiology at UCD, said: “We found that all of the available styrene was converted by the bacteria into plastic, completely removing the pollutant.

“The plastic made by the bacteria has a wide range of industrial and commercial uses such as medical implants, scaffolds for tissue engineering, wound management, drug carriers, plastic coating of cardboard and in heat-resistant plastic.”

The bacterium, which is harmless and lives in most Irish soil, was isolated for the first time by Cork-based scientist Alan Dobson several years ago. O’Connor was part of the team and has continued to research its possible economic uses.

Now they are ready for larger-scale tests to check if the process is commercially viable.

Styrene is found in many types of industrial effluent. In Ireland it is produced as a by-product of the drugs industry. It is stored and later exported to be burnt in hazardous-waste incinerators.

The waste-disposal method being developed by UCD would have health as well as economic benefits. Exposure to styrene causes lung irritation, muscle weakness, and brain and nervous system damage in both humans and animals. Its release into the air by incineration is also seen as an environmental problem.

Tony Lowes, chairman of Friends of the Irish Environment, believes bacteria offer a new hope for environmental management.

“A form of bacteria which consumes oil waste in harbours has already had some success in Limerick harbour,” said Lowes. “It has proved an effective, safe alternative to chemicals.”

(Vgl. Meldung vom 2002-12-06.)

Source: Times online Oct. 03, 2004.

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