The researchers are following up an observation that a particular type of termite appears able to eat polythene to see whether the polythene is in fact digested and metabolised. They hope that the termites might offer an environmentally friendly method of disposing of polythene waste.
Chris Kasamba, a researcher at Makerere University in Kampala, Uganda, says that the idea came to him by chance. He was setting up a forest nursery when he noticed that some soldier termites were eating polythene bags intended for holding seedlings. "Instead of looking at [termites] as a menace, I turned around and saw [them] as an opportunity," says Kasamba.
He subsequently set up an experiment at a forest reserve in Namasiga, 90 kilometres east of Kampala, which confirmed that the termites — identified by the Department of Invertebrates at the National Museum of Kenya as Macrotermes herus — could indeed degrade polythene.
But more research is needed. For instance, Kasamba does not know whether the termites digest the polythene, or simply ferry pieces back to their mounds for fungi to digest as they do with wood, which the fungi break down into simpler carbohydrates that they can digest. Alternatively, the polythene may not be digested at all.
Paul Eggleston, an expert on termites from London's Natural History Museum, says the process that is taking place is crucial. "Unless [researchers] have evidence that termites are using plastic as a food and are destroying it as part of their digestive process, then it is very unlikely that it could be used as a way of disposing of plastic," he says. He adds that it is unlikely that either the termites or the fungi would be able to metabolise plastic.
Kasamba, who is studying for a masters degree in environment and natural resources, hopes to find out whether the termite or fungi do metabolise plastic, and if so, what enzyme breaks down the polythene.
Mary Okwakol, a senior lecturer who supervised the research, agrees that more investigation is needed before using termites as biological agents. But she adds that the findings could in theory lead to an environmentally friendly method of disposing of polythene waste. Furthermore, she says that a search of the scientific literature suggests that no one else has done similar work before.
"Biological agents are regarded as environmentally friendly," she says. "So if we [can] find a biological solution to the polythene [bag] problem, that would be a major contribution to environmental protection."
Photo credit: USDA APHIS — Oxford, North Carolina Archives, www.insectimages.org
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