KEY POINTS:
Scientists have created a biological brew that could help Britain clean up a £150 million ($380 million)-a-year environmental blight: discarded chewing gum.
The researchers, based in Manchester, England and Belfast in Northern Ireland, have developed a special solution of enzymes which can break up and dissolve blobs of
gum hardened and stuck to our streets and pavements.
Such lumps can only be removed using cumbersome high pressure steam hoses, costly and noisy freezing machines or corrosive chemicals that damage the environment.
"Our team was having a couple of drinks when talk turned to our disgust at the habit of chewing and spitting gum," said biochemist Dr Gill Stephens of Manchester University.
"Then we began to think of possible solutions and realised there were new biotechnology techniques that could really make a difference."
Britain's chewing gum crisis has grown dramatically in recent years. Gum is now one of the nation's most popular forms of confectionery and consumption has jumped 7 per cent in the past three years.
As a result, a rash of gum blobs has spread across cities and towns. A recent clean-up of Oxford Street in London resulted in 300,000 lumps being removed. At the same time, the cost of cleaning has become extremely expensive.
In 2007, a piece of gum in the UK cost the equivalent of 7.7c while the price tag for removing it from a street or pavement was 26c.
But now researchers at Belfast and Manchester believe they have found a simple answer: enzymes. These are tiny molecular scissors used by living organisms to cut and break up long chemical chains. Enzymes are crucial to our digestive system, for example.
"Enzymes were just what we needed, we realised," said Dr Stephens. "There was a problem, however. Chewing gum - which is essentially a form of synthetic rubber - is hydrophobic: it repels water. That meant we could not use it as the basis of an enzyme solution. We needed something else."
Other widely used solvents, such as acetone and ether, are either poisonous or inflammable and so could not be released in public places.
Then researchers at Queen's University, Belfast, led by Professor Kenneth Seddon, came up with using substances known as ionic liquids.
These are organic salts with low melting points and have recently been employed as alternatives to the traditional organic solvents. Crucially, most ionic liquids are biodegradable.
The two sets of researchers formed a joint group and raised a £1 million ($2.5 million) development fund, half from government sources and the rest from industry. For the past two years, they have been testing various ionic liquids in combination with different types of enzymes.
Dr Stephens said: "We have chewed gum, stuck them on pieces of pavement or tar and then added our different solutions to see which works best ...
"We have now got a small selection of solutions and are testing these to find out their reactions to water and temperature and to determine what damage they might do to the environment, including any possible damage that they might do to the soles of people's shoes.
"Once we get that right, in about a year, we can begin to think of commercial development."
CHEW ON IT
* Wrigley and Cadbury Schweppes account for 60 per cent of the world market in chewing gum
* A packet of Wrigley's gum was the first item to be scanned by a barcode reader
* It is illegal to import chewing gum into Singapore
- OBSERVER
