title: Microbial communities and greenhouse gas emissions associated with the biodegradation of specified risk material in compost.
abstract: Provided that infectious prions (PrP(Sc)) are inactivated, composting of specified risk material (SRM) may be a viable alternative to rendering and landfilling. In this study, bacterial and fungal communities as well as greenhouse gas emissions associated with the degradation of SRM were examined in laboratory composters over two 14 day composting cycles. Chicken feathers were mixed into compost to enrich for microbial communities involved in the degradation of keratin and other recalcitrant proteins such as prions. Feathers altered the composition of bacterial and fungal communities primarily during the first cycle. The bacterial genera Saccharomonospora, Thermobifida, Thermoactinomycetaceae, Thiohalospira, Pseudomonas, Actinomadura, and Enterobacter, and the fungal genera Dothideomycetes, Cladosporium, Chaetomium, and Trichaptum were identified as candidates involved in SRM degradation. Feathers increased (P<0.05) headspace concentrations of CH4 primarily during the early stages of the first cycle and N2O during the second. Although inclusion of feathers in compost increases greenhouse gas emissions, it may promote the establishment of microbial communities that are more adept at degrading SRM and recalcitrant proteins such as keratin and PrP(Sc).
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Shanwei
authors.initials: S
authors.lastname: Xu
authors.forename: Tim
authors.initials: T
authors.lastname: Reuter
authors.forename: Brandon H
authors.initials: BH
authors.lastname: Gilroyed
authors.forename: Lisa
authors.initials: L
authors.lastname: Tymensen
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Hao
authors.forename: Xiying
authors.initials: X
authors.lastname: Hao
authors.forename: Miodrag
authors.initials: M
authors.lastname: Belosevic
authors.forename: Jerry J
authors.initials: JJ
authors.lastname: Leonard
authors.forename: Tim A
authors.initials: TA
authors.lastname: McAllister
mesh_terms: D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D002417:Cattle; D002645:Chickens; D005241:Feathers; D005658:Fungi / Q000235:genetics / Q000378:metabolism; D005740:Gases; D006256:Hazardous Waste; D007633:Keratins / Q000378:metabolism; D008372:Manure; D008697:Methane / Q000378:metabolism; D059013:Microbial Consortia / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009609:Nitrous Oxide / Q000378:metabolism; D010802:Phylogeny; D011328:Prions / Q000378:metabolism; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012988:Soil Microbiology
chemical_list: D005740:Gases; D006256:Hazardous Waste; D008372:Manure; D011328:Prions; D012336:RNA, Ribosomal, 16S; D012987:Soil; D007633:Keratins; D009609:Nitrous Oxide; D008697:Methane