Correlating denitrifying catabolic genes with N2O and N2 emissions from swine slurry composting

• Published in: Bioresource technology Vol. 140; pp. 368 - 375
• Main Authors: Angnes, G., Nicoloso, R.S., da Silva, M.L.B., de Oliveira, P.A.V., Higarashi, M.M., Mezzari, M.P., Miller, P.R.M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2013; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Ammonia - analysis; Animal productions; Animals; Bacteria; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biotechnology; Carbon Dioxide - analysis; Composting; Correlation; Denitrification; Denitrification - genetics; Environment and pollution; Functional genes; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Genes; Genes, Bacterial - genetics; Greenhouse gases; Humidity; Industrial applications and implications. Economical aspects; Methane - analysis; Nitrification; Nitrification - genetics; Nitrogen - analysis; Nitrous Oxide - analysis; Nitrous oxides; Piles; qPCR; Slurries; Soil; Sus scrofa; Swine; Temperature; Terrestrial animal productions; Time Factors; Use of agricultural and forest wastes. Biomass use, bioconversion; Vertebrates; Denitrification; qPCR; Greenhouse gases; Functional genes; Nitrification; Farming animal; Animal slurry; Pig barn; Pig; Vertebrata; Composting; Mammalia; Nitrogen Molecules; Gene; Greenhouse gas; Catabolism; Artiodactyla; Nitrogen protoxide; Ungulata
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.04.112

•Denitrifying catabolic genes were used to infer on N2O and N2 losses during swine slurry composting.•During the thermophilic composting stage most of the N losses occurred as NH3 and N2 emissions.•Changes in norB and nosZ genes abundance were indicative of N2O emissions.•The catabolic narG, nirS, and nosZ genes were significantly correlated with N2 emission.•Functional genes were useful to estimate N emissions and minimize uncertainties on mass balances. This work evaluated N dynamics that occurs over time within swine slurry composting piles. Real-time quantitative PCR (qPCR) analyzes were conducted to estimate concentrations of bacteria community harboring specific catabolic nitrifying-ammonium monooxygenase (amoA), and denitrifying nitrate- (narG), nitrite- (nirS and nirG), nitric oxide- (norB) and nitrous oxide reductases (nosZ) genes. NH3-N, N2O-N, N2-N emissions represented 15.4±1.9%, 5.4±0.9%, and 79.1±2.0% of the total nitrogen losses, respectively. Among the genes tested, temporal distribution of narG, nirS, and nosZ concentration correlated significantly (p<0.05) with the estimated N2 emissions. Denitrifying catabolic gene ratio (cnorB+qnorB)/nosZ⩾100 was indicative of N2O emission potential from the compost pile. Considering our current empirical limitations to accurately measure N2 emissions from swine slurry composting at field scale the use of these catabolic genes could represent a promising monitoring tool to aid minimize our uncertainties on biological N mass balances in these systems.