Polyurethane has diverse applications in a host of products ranging from furniture fillings to shoe soles, cable insulation and paints. PU can be difficult to recycle, but could soon be degraded in compost heaps, thanks to a study at the University of Manchester, as per PhysOrg.org. Dr Geoff Robson and his team at the Faculty of Life Sciences have found that certain fungi can degrade the plastic in soil. Further more the rate of degradation increases when the volume of these fungi is increased or nutrients are added to the soil to boost the fungi’s activity. The team placed polyurethane pieces in soil containing fungi and bacteria. As the polyurethane, which is made from petroleum, degraded, the number of fungi increased as they digested the byproducts, showing that it was indeed the fungi that were breaking down the plastic. They are now carrying out further studies to make sure the degradation of polyurethanes does not adversely affect the composting process or its products. Dr Robson, whose Biotechnology and Biological Sciences Research Council (BBSRC) funded study is published in the Applied and Environmental Microbiology, said: “This is a significant finding. This study opens the possibility that fungi could be used to degrade these materials instead of dumping them into landfill sites.” The team demonstrated increased degradation of polyurethanes when buried in soil either by enhancing the activity of fungi already present by adding nutrients to the soil or by adding specific fungi to the soil that had previously been isolated from the surface of degrading polyurethane.” The team is now investigating how best to apply their findings to polyurethane waste management. One possible method would be to spray fungi onto the polyurethane but another method would be to compost polyurethane along with other compostable materials - using already existing facilities.
Organisms discovered by Yale undergraduates growing within fungi in the Amazon Rainforest can degrade polyurethane, as per PhysOrg.org. The paper, accepted for publication in July by the journal Applied and Environmental Microbiology, is the work of undergraduates who participated in Yale's Rainforest Expedition and Laboratory course, funded by the Howard Hughes Medical Institute. Students taking the course search for and collect organisms called endophytes found in rainforest plants and then take them back to New Haven to test them for biological activity. Students analyze the endophytes that show biological activity to see whether they might have other medical or other social uses. On the trip to Equador, they decided to see if the endophytes collected could be used in bioremediation. In a rudimentary test, Anand showed a chemical reaction did take place when an endophyte she found was introduced to plastic. Another undergraduate Jeffrey Huang analyzed endophytes collected by other students on the 2008 trip to find those that broke down chemical bonds most efficiently. Jonathan R. Russell discovered that one family of endophytes identified by Huang showed the most promise for bioremediation. Russell went on to identify the enzyme that most efficiently broke down polyurethane. While other agents can degrade polyurethane, the enzyme identified by Yale students holds particular promise because it also degrade plastic in the absence of oxygen - a prerequisite for bioremediation of buried trash. Also, a new group of undergraduates are analyzing newly discovered endophytes collected during recent rainforest trips to see if they can also degrade more intractable plastics such as polystyrene.