A group of students and professors from Yale University have found a fungi in the Amazon rainforest that can degrade and utilize the common plastic polyurethane (PUR). As part of the university’s Rainforest Expedition and Laboratory educational program, designed to engage undergraduate students in discovery-based research, the group searched for plants and cultured the micro-organisms within their tissue.
Several active organisms were identified, including two distinct isolates of Pestalotiopsis microspora with the ability to efficiently degrade and utilize PUR as the sole carbon source when grown anaerobically, a unique observation among reported PUR biodegradation activities.
Polyurethane is a big part of our mounting waste problem and this is a new possible solution for managing it. The fungi can survive on polyurethane alone and is uniquely able to do so in an oxygen-free environment. The Yale University team has published its findings in the article ‘Biodegradation of Polyester Polyurethane by Endophytic Fungi’ for the Applied and Environmental Microbiology journal.
Biodegradation of Polyester Polyurethane by Endophytic Fungi
Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation.