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

Abstract

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.

Effect of turning frequency and season on composting materials from swine high-rise facilities

“…In these composts, concentrations of denitrifiers were similar in FT and ST composts and there were no significant differences in concentrations between samples regardless of turning frequency, compost time or season (Table 5). This is in contrast to findings of Angnes et al (2013) and Wang et al (2013) which showed that concentrations of genes for denitrification (i.e., norB, nosZ, nirK and nirS) varied over the course of composting and that the concentrations were correlated with N 2 O emissions in swine slurry composts. These HRFF materials had been accumulated/ stored and partially decomposed while under the high-rise facilities for two to three months prior to composting, likely permitting accumulation of denitrifiers and accounting for higher concentrations in the initial compost materials.…”

“…Recent research on swine slurry composting and its application to agricultural soils has provided new insights into how swine slurry compost management (turning, moisture, bulking material, temperature, etc.) affects nitrogen dynamics (Angnes et al, 2013;Fukumoto et al, 2009), green house gas emissions (Fukumoto et al, 2003;Selvam et al, 2012;Zhong et al, 2013), pharmaceuticals (Derby et al, 2011) and microbial populations (Kuok et al, 2012;Mc Carthy et al, 2011;Pan et al, 2013).…”

Enhanced long-term ammonium removal and its ranked contribution of microbial genes associated with nitrogen cycling in a lab-scale multimedia biofilter

“…This is supported by previous studies that decreased C/N ratio had a significant negative impact on bacterial and archaeal community (Goldman et al, 1987;Satoh et al, 2000). Although archaeal showed a much lower abundance (relative to bacteria), these small parts of the archaeal community may play a vital roles in nitrogen removal and greenhouse gas emissions (Angnes et al, 2013;Leininger et al, 2006).…”

Quantifying nitrogen transformation process rates using nitrogen functional genesin a multimedia biofilter under hydraulic loading rate constraints

“…The current study supported previous work indicating that Archaeal 16S rRNA are dominant among the ammonia-oxidizing prokaryotes in soils (Leininger et al, 2006). Although the archaea were not dominant in the microbial community during Stages I to V in the current study, they may potentially play vital roles in nitrogen transformation and removal (Angnes et al, 2013). Fig.…”