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1.
Pertti J. Martikainen Marja Lehtonen Kristiina Lång Wiestse De Boer Ari Ferm 《FEMS microbiology ecology》1993,13(2):113-121
Abstract Using aerobic soil slurry technique nitrification and nitrous oxide production were studied in samples from a pine site in Western Finland. The site received atmospheric ammonium deposition of 7–33 kg N ha−1 a−1 from a mink farm. The experiments with soil slurries showed that the nitrification potential in the litter layer was higher at pH 6 than at pH 4. However, the nitrification potentials in the samples from the organic and mineral horizons at pH 6 and 4 were almost equal. Also N2 O was produced at a higher rate at pH 6 than at pH 4 in slurries of the litter layer samples. The reverse was true for samples from the organic and mineral horizons. The highest N2 O production and nitrification rates were measured in the suspensions of litter layer samples. Nitrification activity in field-moist soil samples was lower than the activity in the slurries indicating that the availability of ammonium limited nitrification in these soils. Acetylene (2.5 kPa) retarded nitrification activity (70-–100%) and N2 O production (40 – 90%) in soil slurries. Acetylene inhibited the N2 O production by 40–60% during the first 3 days after its addition to field-moist samples incubated in aerobic atmosphere. After 3 days the inhibition became much lower (4–5%). The results indicate that, in soil profiles of boreal coniferous forests receiving ammonium deposition, chemolithotrophic nitrification may have importance in the N2 O production, and that changes in soil pH affect differently nitrification as well as N2 O production in litter and deeper soil layers. 相似文献
2.
Metabolism of nitric oxide and nitrous oxide during nitrification and denitrification in soil at different incubation conditions 总被引:1,自引:0,他引:1
Abstract NO production and consumption rates as well as N2 O accumulation rates were measured in a loamy cambisol which was incubated under different conditions (i.e. soil moisture content, addition of nitrogen fertilizer and/or glucose, aerobic or anaerobic gas phase). Inhibition of nitrification with acetylene allowed us to distinguish between nitrification and denitrification as sources of NO and N2 O. Under aerobic conditions untreated soil showed very low release of NO and N2 O but high consumption of NO. Fertilization with NH4 + or urea stimulated both NO and N2 O production by nitrification. Addition of glucose at high soil moisture contents led to increased N2 and N2 O production by denitrification, but not to increased NO production rates. Anaerobic conditions, however, stimulated both NO and N2 O production by denitrification. The production of NO and N2 O was further stimulated at low moisture contents and after addition of glucose or NO3 − . Anaerobic consumption of NO by denitrification followed Michaelis-Menten kinetics and was stimulated by addition of glucose and NO3 − . Aerobic consumption of NO followed first-order kinetics up to mixing ratios of at least 14 ppmv NO, was inhibited by autoclaving but not by acetylene, and decreased with increasing soil moisture content. The high NO-consumption activity and the effects of soil moisture on the apparent rates of anaerobic and aerobic production and consumption of NO suggest that diffusional constraints have an important influence on the release of NO, and may be a reason for the different behaviour of NO release vs N2 O release. 相似文献
3.
Metabolism of nitric oxide and nitrous oxide during nitrification and denitrification in soil at different incubation conditions 总被引:4,自引:0,他引:4
Abstract NO production and consumption rates as well as N2 O accumulation rates were measured in a loamy cambisol which was incubated under different conditions (i.e. soil moisture content, addition of nitrogen fertilizer and/or glucose, aerobic or anaerobic gas phase). Inhibition of nitrification with acetylene allowed us to distinguish between nitrification and denitrification as sources of NO and N2 O. Under aerobic conditions untreated soil showed very low release of NO and N2 O but high consumption of NO. Fertilization with NH4 + or urea stimulated both NO and N2 O production by nitrification. Addition of glucose at high soil moisture contents led to increased N2 and N2 O production by denitrification, but not to increased NO production rates. Anaerobic conditions, however, stimulated both NO and N2 O production by denitrification. The production of NO and N2 O was further stimulated at low moisture contents and after addition of glucose or NO3 − . Anaerobic consumption of NO by denitrification followed Michaelis-Menten kinetics and was stimulated by addition of glucose and NO3 − . Aerobic consumption of NO followed first-order kinetics up to mixing ratios of at least 14 ppmv NO, was inhibited by autoclaving but not by acetylene, and decreased with increasing soil moisture content. The high NO-consumption activity and the effects of soil moisture on the apparent rates of anaerobic and aerobic production and consumption of NO suggest that diffusional constraints have an important influence on the release of NO, and may be a reason for the different behaviour of NO release vs N2 O release. 相似文献
4.
LYDIE CHAPUIS-LARDY NICOLE WRAGE† AURÉLIE METAY‡ JEAN-LUC CHOTTE§ MARTIAL BERNOUX§ 《Global Change Biology》2007,13(1):1-17
Soils are the main sources of the greenhouse gas nitrous oxide (N2 O). The N2 O emission at the soil surface is the result of production and consumption processes. So far, research has concentrated on net N2 O production. However, in the literature, there are numerous reports of net negative fluxes of N2 O, (i.e. fluxes from the atmosphere to the soil). Such fluxes are frequent and substantial and cannot simply be dismissed as experimental noise.
Net N2 O consumption has been measured under various conditions from the tropics to temperate areas, in natural and agricultural systems. Low mineral N and large moisture contents have sometimes been found to favour N2 O consumption. This fits in with denitrification as the responsible process, reducing N2 O to N2 . However, it has also been reported that nitrifiers consume N2 O in nitrifier denitrification. A contribution of various processes could explain the wide range of conditions found to allow N2 O consumption, ranging from low to high temperatures, wet to dry soils, and fertilized to unfertilized plots. Generally, conditions interfering with N2 O diffusion in the soil seem to enhance N2 O consumption. However, the factors regulating N2 O consumption are not yet well understood and merit further study.
Frequent literature reports of net N2 O consumption suggest that a soil sink could help account for the current imbalance in estimated global budgets of N2 O. Therefore, a systematic investigation into N2 O consumption is necessary. This should concentrate on the organisms, reactions, and environmental factors involved. 相似文献
Net N
Frequent literature reports of net N
5.
Abstract A denitrifying Cytophaga was isolated from soil enriched by anaerobic incubation with glucose, sulfide (S2− ), nitrous oxide (N2 O), and acetylene (C2 H2 ). Such soil enrichments and pure cultures of the isolated Cytophaga reduced N2 O rapidly even in the presence of a normally inhibitory concentration of C2 H2 (4 kPa) providing S2− was present (8 μmol/g soil or 0.4 μmol/ml culture). Since C2 H2 inhibition of the reduction of N2 O is used as a tool in the assay of denitrification, the presence in large numbers of such a Cytophaga may influence the effectiveness of this assay especially in sulfidic environments. 相似文献
6.
Michael Krämer Manfred Baumgärtner Martin Bender Ralf Conrad 《FEMS microbiology letters》1990,73(4):345-350
Abstract The methanotrophs Methylomonas angile (type I) and Methylosinus trichosporium (type II) produced nitrite, nitrate and N2 O during growth on methane, apparently by heterotrophic nitrification of ammonium. The methanotrophs were also able to consume NO but did not produce it. After incubation of soil from a drained paddy field in the presence of CH4 the numbers of methanotrophs increased from 105 to 107 per gram dry weigth. The thus enriched soil showed increased rates of NO consumption while rates of NO production did not change. 相似文献
7.
Mapping field-scale spatial patterns of size and activity of the denitrifier community 总被引:4,自引:0,他引:4
Laurent Philippot Jiri uhel Nicolas P.A. Saby Dominique Chèneby Alicia Chroáková David Bru Dominique Arrouays Fabrice Martin-Laurent Miloslav imek 《Environmental microbiology》2009,11(6):1518-1526
There is ample evidence that microbial processes can exhibit large variations in activity on a field scale. However, very little is known about the spatial distribution of the microbial communities mediating these processes. Here we used geostatistical modelling to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N-cycling, in a grassland field subjected to different cattle grazing regimes. We observed a non-random distribution pattern of the size of the denitrifier community estimated by quantification of the denitrification genes copy numbers with a macro-scale spatial dependence (6–16 m) and mapped the distribution of this functional guild in the field. The spatial patterns of soil properties, which were strongly affected by presence of cattle, imposed significant control on potential denitrification activity, potential N2 O production and relative abundance of some denitrification genes but not on the size of the denitrifier community. Absolute abundance of most denitrification genes was not correlated with the distribution patterns of potential denitrification activity or potential N2 O production. However, the relative abundance of bacteria possessing the nosZ gene encoding the N2 O reductase in the total bacterial community was a strong predictor of the N2 O/(N2 + N2 O) ratio, which provides evidence for a relationship between bacterial community composition based on the relative abundance of denitrifiers in the total bacterial community and ecosystem processes. More generally, the presented geostatistical approach allows integrated mapping of microbial communities, and hence can facilitate our understanding of relationships between the ecology of microbial communities and microbial processes along environmental gradients. 相似文献
8.
Hurricane activity is predicted to increase over the mid-Atlantic as global temperatures rise. Nitrous oxide (N2 O), a greenhouse gas with a substantial source from tropical soils, may increase after hurricanes yet this effect has been insufficiently documented. On September 21, 1998, Hurricane Georges crossed Puerto Rico causing extensive defoliation. We used a before–after design to assess the effect of Georges on N2 O emissions, and factors likely influencing N2 O fluxes including soil inorganic nitrogen pools and soil water content in a humid tropical forest at El Verde, Puerto Rico. Emissions of N2 O up to 7 months post-Georges ranged from 5.92 to 4.26 ng cm−2 h−1 and averaged five times greater than fluxes previously measured at the site. N2 O emissions 27 months after the hurricane remained over two times greater than previously measured fluxes. Soil ammonium pools decreased after Georges and remained low. The first year after the hurricane, nitrate pools increased, but not significantly when compared against a single measurement made before the hurricane. Soil moisture and temperature did not differ significantly in the two sampling periods. These results suggest that hurricanes increase N2 O fluxes in these forests by altering soil N transformations and the relative availabilities of inorganic nitrogen. 相似文献
9.
Lesley A. Robertson Tage Dalsgaard Niels-Peter Revsbech J.Gijs Kuenen 《FEMS microbiology ecology》1995,18(2):113-120
Abstract: Because of a revival in the controversy surrounding 'aerobic denitrification', especially in relation to Thiosphaera pantotropha , activity in aerobic batch cultures was evaluated using gas chromatography and mass spectrometry after the addition of 15 N-labelled NH4 + and NO2 − . Aerobic denitrifying activity in T. pantotropha was present, but only at about 10% of the originally-reported levels. The activity of ' Pseudomonas denitrificans ' was similar to previously-reported values. Alcaligenes faecalis showed significant aerobic denitrifying activity, producing almost equivalent amounts of N2 and N2 O. An unidentified pseudomonad, isolate G4, presumably requires anoxia for enzyme activity as it did not denitrify aerobically, even though it has a constitutive denitrifying pathway. 相似文献
10.
JANET E. BERTRAM TIM J. CLOUGH ROBERT R. SHERLOCK LEO M. CONDRON MAUREEN O'CALLAGHAN† NAOMI S. WELLS JESSICA L. RAY 《Global Change Biology》2009,15(8):2067-2077
Atmospheric concentrations of the greenhouse gas nitrous oxide (N2 O) have continued to rise since the advent of the industrial era, largely because of the increase in agricultural land use. The urine deposited by grazing ruminant animals is a major global source of agricultural N2 O. With the first commitment period for reducing greenhouse gas emissions under the Kyoto Protocol now underway, mitigation options for ruminant urine N2 O emissions are urgently needed. Recent studies showed that increasing the urinary concentration of the minor urine constituent hippuric acid resulted in reduced emissions of N2 O from a sandy soil treated with synthetic bovine urine, due to a reduction in denitrification. A similar effect was seen when benzoic acid, a product of hippuric acid hydrolysis, was used. This current laboratory experiment aimed to investigate these effects using real cow urine for the first time. Increased concentrations of hippuric acid or benzoic acid in the urine led to reduction of N2 O emissions by 65% (from 17% to <6% N applied), with no difference between the two acid treatments. Ammonia volatilization did not increase significantly with increased hippuric acid or benzoic acid concentrations in the urine applied. Therefore, there was a net reduction in gaseous N loss from the soil with higher urinary concentrations of both hippuric acid and benzoic acid. The results show that elevating hippuric acid in the urine had a marked negative effect on both nitrification and denitrification rates and on subsequent N2 O fluxes. This study indicates the potential for developing a novel mitigation strategy based on manipulation of urine composition through ruminant diet. 相似文献
11.
Abstract Denitrification rates were measured as N2 O production in two water-logged forest soils at monthly intervals. The effect of acetylene inhibition and the addition of nitrate, glucose, acetate and celloboise in field incubations was examined.
N2 O release from the two soils was very low, 26 mg N2 m−2 y−1 in ash and 178 mg N2 in alder. In acetylene inhibited incubations N2 O production was higher, 296 and 486 mg N2 m−2 y−1 in ash and alder respectively. After addition of nitrate and C-sources to a 10 mM concentration, denitrification rates increased to 5–15 times higher values.
The denitrification rates below 4°C were low and most N2 O was produced in late spring and summer.
The highest rate of denitrification during a 50 h incubation experiment occurred between 3 and 23 h. 相似文献
N
The denitrification rates below 4°C were low and most N
The highest rate of denitrification during a 50 h incubation experiment occurred between 3 and 23 h. 相似文献
12.
Snow depth, soil freezing, and fluxes of carbon dioxide, nitrous oxide and methane in a northern hardwood forest 总被引:14,自引:0,他引:14
PETER M. GROFFMAN JANET P. HARDY† CHARLES T. DRISCOLL‡ TIMOTHY J. FAHEY§ 《Global Change Biology》2006,12(9):1748-1760
Soil–atmosphere fluxes of trace gases (especially nitrous oxide (N2 O)) can be significant during winter and at snowmelt. We investigated the effects of decreases in snow cover on soil freezing and trace gas fluxes at the Hubbard Brook Experimental Forest, a northern hardwood forest in New Hampshire, USA. We manipulated snow depth by shoveling to induce soil freezing, and measured fluxes of N2 O, methane (CH4 ) and carbon dioxide (CO2 ) in field chambers monthly (bi-weekly at snowmelt) in stands dominated by sugar maple or yellow birch. The snow manipulation and measurements were carried out in two winters (1997/1998 and 1998/1999) and measurements continued through 2000. Fluxes of CO2 and CH4 showed a strong seasonal pattern, with low rates in winter, but N2 O fluxes did not show strong seasonal variation. The snow manipulation induced soil freezing, increased N2 O flux and decreased CH4 uptake in both treatment years, especially during winter. Annual N2 O fluxes in sugar maple treatment plots were 207 and 99 mg N m−2 yr−1 in 1998 and 1999 vs. 105 and 42 in reference plots. Tree species had no effect on N2 O or CO2 fluxes, but CH4 uptake was higher in plots dominated by yellow birch than in plots dominated by sugar maple. Our results suggest that winter fluxes of N2 O are important and that winter climate change that decreases snow cover will increase soil:atmosphere N2 O fluxes from northern hardwood forests. 相似文献
13.
Abstract Samples of water, sediment and bacterial mat from hot springs in Grændalur and Hveragerdi areas in southwestern Iceland were screened at 70°C and 80°C for thermophilic denitrifying bacteria by culturing in anaerobic media containing nitrate or N2 O as the terminal oxidant. The springs ranged in temperature from 65–100°C and included both neutral (pH 7–8.5) and acidic (pH 2.5–4) types. Nitrate reducing bacteria (nitrate → nitrite) and denitrifiers (nitrate → N2 ) were found that grew at 70°C but not at 80°C in nutrient media at pH 8. Samples from neutral springs that were cultured at pH 8 failed to yield a chemolithotrophic, sulfur-oxidizing and nitrate-reducing bacterium, and samples from acidic springs that were cultured at pH 3.5 seemed entirely to lack dissimilatory, nitrate-utilizing bacteria. No sample yielded an organism capable of growth solely by N2 O respiration. The denitrifiers appeared to be Bacillus . Two such Bacillus strains were examined in pure culture and found to exhibit the unusual denitrification phenotype described previously for the mesophile, Pseudomonas aeruginosa , and one other strain of thermophilic Bacillus . The phenotype is characterized by the ability to grow by reduction of nitrate to N2 with N2 O as an intermediate but a virtual inability to reduce N2 O when N2 O was the sole oxidant. 相似文献
14.
Abstract Samples of water, sediment and bacterial mat from hot springs in Grændalur and Hveragerdi areas in southwestern Iceland were screened at 70°C and 80°C for thermophilic denitrifying bacteria by culturing in anaerobic media containing nitrate or N2 O as the terminal oxidant. The s springs ranged in temperature from 65–100°C and included both neutral (pH 7–8.5) and acidic (pH 2.5–4) types. Nitrate reducing bacteria (nitrate → nitrite) and denitrifiers (nitrate → N2 ) were found that grew at 70°C but not at 80°C in nutrient media at pH 8. Samples from neutral springs that were cultured at pH 8 failed to yield a chemolithotrophic, sulfur-oxidizing and nitrate-reducing bacterium, and samples from acidic springs that were cultured at pH 3.5 seemed entirely to lack dissimilatory, nitrate-utilizing bacteria. No sample yielded an organism capable of growth solely by N2 O respiration. The denitrifiers appeared to be Bacillus . Two such Bacillus strains were examined in pure culture and found to exhibit the unusual denitrification phenotype described previously for the mesophile, Pseudomonas aeruginosa , and one other strain of thermophilic Bacillus . The phenotype is characterized by the ability to grow by reduction of nitrate to N2 with N2 O as an intermediate but a virtual inability to reduce N2 O when N2 O was the sole oxidant. 相似文献
15.
Ecosystem CO2 and N2 O exchanges between soils and the atmosphere play an important role in climate warming and global carbon and nitrogen cycling; however, it is still not clear whether the fluxes of these two greenhouse gases are correlated at the ecosystem scale. We collected 143 pairs of ecosystem CO2 and N2 O exchanges between soils and the atmosphere measured simultaneously in eight ecosystems around the world and developed relationships between soil CO2 and N2 O fluxes. Significant linear regressions of soil CO2 and N2 O fluxes were found for all eight ecosystems; the highest slope occurred in rice paddies and the lowest in temperate grasslands. We also found the dominant role of growing season on the relationship of annual CO2 and N2 O fluxes. No significant relationship between soil CO2 and N2 O fluxes was found across all eight ecosystem types. The estimated annual global N2 O emission based on our findings is 13.31 Tg N yr−1 with a range of 8.19–18.43 Tg N yr−1 for 1980–2000, of which cropland contributes nearly 30%. Our findings demonstrated that stoichiometric relationships may work on ecological functions at the ecosystem level. The relationship of soil N2 O and CO2 fluxes developed here could be helpful in biogeochemical modeling and large-scale estimations of soil CO2 and N2 O fluxes. 相似文献
16.
Tatsuo Tanimoto Ken-ichi Hatano Du-hyun Kim Hiroo Uchiyama Hirofumi Shoun 《FEMS microbiology letters》1992,93(2):177-180
Abstract Nitrogen compounds such as azide, salicylhydroxamic acid, and possibly ammonium ions were converted to nitrous oxide (N2 O) or dinitrogen (N2 ) by Fusarium oxysporum under denitrifying conditions. Nitrogen atoms in these compounds were combined with another nitrogen atom from nitrite to form a hybrid N2 O species. The fungus exhibited much higher converting activities as compared with similar reactions catalyzed by bacterial denitrifiers. We thus propose the phenomenon be called co-denitrification, which means that such nitrogen compounds are denitrified by the system induced by nitrite (or nitrate) but are incapable by themselves of inducing the denitrifying system. 相似文献
17.
Denitrification and nitrate-reducing bacterial populations in abandoned and reclaimed minesoils 总被引:1,自引:0,他引:1
Abstract Microbial populations, nitrogen mineralization potentials, and denitrification enzyme activities were examined in two abandoned carbolithic minesoils. Numbers and activities of bacteria and fungi were lower in nonamended than in lime and/or fly ash amended sites. Rates of aerobic NO3 − production (3 to 38 μg-N kg−1 h−1 ) and anaerobic NO3 − reduction to N2 O (5 to 68 μg-N kg−1 h−1 ) were measured. Organisms capable of N2 O production under anaerobic soil conditions were present in low numbers, and their activity was restricted in part by low soil pH. Nondenitrifying nitrate-reducing bacteria were more diverse and in greater numbers than respiratory denitrifiers and may have been responsible for N2 O production in assays measuring denitrification enzyme activity. 相似文献
18.
Measurement of denitrification in estuarine sediment using membrane inlet mass spectrometry 总被引:1,自引:0,他引:1
Abstract Denitrification was measured in intact sediment cores and in homogenised slurries using membrane inlet mass spectrometry. Dissolved concentrations of O2 , N2 , N2 O and CO2 were simultaneously monitored. Using a 0.8 mm diameter needle probe, a comparison was made of the gas profiles of intact cores obtained under different conditions, i.e. with air or argon as the headspace gas and after the addition of nitrate and/or a carbon source to the sediment surface. O2 was detectable to a depth of 1 cm under a headspace of air and the depth at which the maxima of denitrification products occurred was 1.5–2 cm. Denitrification products (N2 O, N2 ) occurred in the surface layers where O2 was above the minimum level of detectability (> 0.25 μM): diffusion of N2 and N2 O upwards from the anoxic zone, local anaerobic microenvironments or aerobic denitrification are alternative explanations for this observation. The addition of nitrate and/or acetate increased the concentrations of N2 , N2 O and CO2 in the sediment core. In sediment slurries, the pH, nitrate concentration, carbon source and the depth from which the sample was taken affected the rate of denitrification. Nitrogen was the sole detectable end product. Maximum denitrification occurred at pH 7.5 and at 20 mM nitrate. Denitrification was at a maximum in those slurries prepared from sections of core at 1–2 cm depth. 相似文献
19.
Denitrification in river sediments: relationship between process rate and properties of water and sediment 总被引:6,自引:0,他引:6
1. A survey was made of denitrification and nitrous oxide (N2 O) production in river sediments at fifty sites in north‐east England during one season in order to investigate the relationship between rates and environmental factors likely to influence these processes. The sites were chosen to represent a wide range of physical and chemical conditions. Denitrification rate and N2 O production were measured within 5 h of sampling using the slurry acetylene blockage technique.
2. Denitrification rate ranged from less than 0.005–260 nmol N g–1 DW h–1 , tending to increase in a downstream direction. N2 O production ranged from negative values (net consumption) to 13 nmol N2 O‐N g–1 DW h–1 and accounted for 0–115% of the N gases produced.
3. Denitrification rate and N2 O concentration in the sediment were correlated positively with nitrate concentration in the water column, water content of the sediment and percentage of fine (< 100 μm) particles in the sediment.
4. The variation in denitrification rate was satisfactorily explained (64% total variance) by a model employing measurements of water nitrate and water content of sediments. No simple or multiple relationship was found for N2 O production. 相似文献
2. Denitrification rate ranged from less than 0.005–260 nmol N g
3. Denitrification rate and N
4. The variation in denitrification rate was satisfactorily explained (64% total variance) by a model employing measurements of water nitrate and water content of sediments. No simple or multiple relationship was found for N
20.
Nitrous oxide (N2 O) is a powerful greenhouse gas. The UK government is committed to reducing all greenhouse gas emissions and is required to make an inventory of the sources and emissions of these gases. Here, we extend work from a pilot study at the catchment scale reported in an earlier paper. This paper reports on the upscaling measurements of emissions to derive annual emission rates for specific combinations of soil type, land management and fertiliser practices to the national scale. Digital soil, climate and land use maps were combined within Geographic Information Systems (GIS) software. Upscaling of field emissions measurements involves adjusting measured annual N2 O emissions to fit combinations of crop growth cycles, soil wetness and the amount and timing of fertiliser applications. We have also taken account of the differences in emission rates from grazed pasture land due to differences in land management between land utilised for dairy production and land utilised for beef production. Calculated annual emission rates were then spatially scaled to derive national figures through the use of a GIS modelling framework, termed NitOx. The annual emission of N2 O from Scotland was determined as approximately 6 000 000 kg N yr−1 (2.8 Mt carbon dioxide (CO2 ) equivalents) and compares favourably with other national scale estimates such as the IPCC (1997) . The combination of animal grazing, high N inputs, climatic warmth and poorly drained soils means that the south west contributes significantly to the national total N2 O emissions. Localised areas of high emission can also be identified, but identification could be improved by applying this modelling approach at a larger scale. It would be beneficial to target these areas with mitigation strategies. 相似文献