London, May 18 - Researchers have discovered a fungus in the Amazon rainforest that can break down the common plastic polyurethane, used in billions of discarded plastic bottles.

Their pile-up, amounting to one billion tonnes since 1950s, is threatening to choke many of the eco systems so vital for survival of life. The synthetic material, derived from petrochemicals, degrades very slowly because of its complex chemical bonds.

One of the most widely used plastics, the global consumption of polyurethane raw materials in 2007 was above 12 million tons, with an average annual growth rate in its use of about five percent, the journal Applied and Environmental Microbiology reports.

Researchers from Yale University, Connecticut's Rainforest Expedition and lab educational programme, scoured the Ecuadorian rainforest for plants and cultured the micro-organisms within their tissue, according to the Daily Mail.

"Endophytes were isolated from plant stems collected in the Ecuadorian rainforest. A subset of these organisms was screened for their ability to degrade polyurethane," the researchers said.

Endophytes are micro-organisms that live within the inner tissues of plants, but do not cause any noticeable disease symptoms in their hosts. They often play a key role in the decomposition of the plants after death, but never before have they been tested for their ability to degrade synthetic materials.

The authors of the study hold out hope that further exploration of properties of endophytes could reveal more miracle metabolisers that could potentially be used to degrade other kinds of plastics.