Biodegradation of polyester polyurethane during commercial composting and analysis of associated fungal communities.

In this study the biodegradation of polyurethane (PU) during the maturation stage of a commercial composting process was investigated. PU coupons were buried in the centre and at the surface of a 10 m high compost pile. Fungal communities colonising polyester PU coupons were compared with the native compost communities using culture based and molecular techniques. Putative polyester PU degrading fungi were ubiquitous in compost and rapidly colonised the surface of polyester PU coupons with significant deterioration. As the temperature decreased, fungal diversity in the compost and on the surface of the polyester PU coupons increased and selection of fungal community on the polyester PU coupons occurs that is different from the surrounding compost.

Fungal succession in an in-vessel composting system characterized using 454 pyrosequencing.

Fungi are known to have an important role in the composting process as degraders of recalcitrant materials such as cellulose and lignin. Previous attempts to study the diversity and succession of fungi in compost systems have relied on the use of culture-dependent analyses and low-resolution DNA-fingerprinting techniques, lacking the necessary depth to analyse such a rich ecosystem. In this study, 454 pyrosequencing was used to characterize the fungal community composition at the different stages of an in-vessel composting process. A complex succession of fungi was revealed, with 251 fungal OTUs identified throughout the monitoring period. The Ascomycota were the dominant phylum (82.5% of all sequences recovered), followed by the Basidiomycota (10.4%) and the subphylum Mucoromycotina (4.9%). In the starting materials and early stages of the process, yeast species from the Saccharomycetales were abundant, while in latter stages and in the high temperature regions of the pile, fungi from the orders Eurotiales, Sordariales, Mucorales, Agaricales and Microascales were the most prominent. This study provides an improved understanding of the fungal diversity occurring during the composting of municipal solid waste, and this knowledge can lead to the development of more efficient composting practices and a better evaluation of the end-product quality.