title: Evolution of clostridia and streptomycetes in full-scale composting facilities and pilot drums equipped with on-line temperature monitoring and aeration.
abstract: The evolution of sporulating bacteria in full-scale composting facilities with online temperature monitoring has been poorly studied, although organic matter recycling increases. We analysed Clostridium perfringens and sulphite-reducing clostridia (SRC) by cultivation, and streptomycetes by real-time PCR in five full-scale, temperature-monitored and aerated composting processes, and two pilot-scale drum composters. Facilities composted woodchips, sawdust, peat, or bark amended sludge or source-separated biowaste. Streptomycetes genes of 0.21-110×10(7)copies/g feed increased fast to 0.019-33×10(9)copies/g, and then were equal or decreased. SRC of 0.06-2.2×10(7)cfu/g feed decreased to 0-600 cfu/g, with re-growth in two facilities. End products were clean of C. perfringens, detected in sludge composts. Although processes contained large quantities of spore-forming bacteria, in the best facilities end products had the high quality. Temperature (>55°C,>2d) was not related to the end compost quality, but relations between waste and bulking agent qualities, aeration, and processing time should be better controlled.
authors: Helsinki University, Department of Environmental Sciences, Niemenkatu 73, 15140 Lahti, Finland.
authors: Aija
authors: A
authors: Rainisalo
authors: Martin
authors: M
authors: Romantschuk
authors: Merja H
authors: MH
authors: Kontro
mesh_terms: D001483:Base Sequence; D003013:Clostridium / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics; D010100:Oxygen; D060888:Real-Time Polymerase Chain Reaction; D012987:Soil; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism*; D013696:Temperature
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D012987:Soil; D010100:Oxygen