scholarly journals Potential of Aerobic Denitrification by Pseudomonas stutzeri TR2 To Reduce Nitrous Oxide Emissions from Wastewater Treatment Plants

2010 ◽  
Vol 76 (14) ◽  
pp. 4619-4625 ◽  
Author(s):  
Morio Miyahara ◽  
Sang-Wan Kim ◽  
Shinya Fushinobu ◽  
Koki Takaki ◽  
Takeshi Yamada ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Bacterial Species ◽  
Pseudomonas Stutzeri ◽  
Sharp Contrast ◽  
Nitrous Oxide Emissions ◽  
Aerobic Denitrification ◽  
Piggery Wastewater ◽  
Lower Growth ◽  
Aerobic Conditions ◽  
Denitrification Activity

ABSTRACT In contrast to most denitrifiers studied so far, Pseudomonas stutzeri TR2 produces low levels of nitrous oxide (N2O) even under aerobic conditions. We compared the denitrification activity of strain TR2 with those of various denitrifiers in an artificial medium that was derived from piggery wastewater. Strain TR2 exhibited strong denitrification activity and produced little N2O under all conditions tested. Its growth rate under denitrifying conditions was near comparable to that under aerobic conditions, showing a sharp contrast to the lower growth rates of other denitrifiers under denitrifying conditions. Strain TR2 was tolerant to toxic nitrite, even utilizing it as a good denitrification substrate. When both nitrite and N2O were present, strain TR2 reduced N2O in preference to nitrite as the denitrification substrate. This bacterial strain was readily able to adapt to denitrifying conditions by expressing the denitrification genes for cytochrome cd 1 nitrite reductase (NiR) (nirS) and nitrous oxide reductase (NoS) (nosZ). Interestingly, nosZ was constitutively expressed even under nondenitrifying, aerobic conditions, consistent with our finding that strain TR2 preferred N2O to nitrite. These properties of strain TR2 concerning denitrification are in sharp contrast to those of well-characterized denitrifiers. These results demonstrate that some bacterial species, such as strain TR2, have adopted a strategy for survival by preferring denitrification to oxygen respiration. The bacterium was also shown to contain the potential to reduce N2O emissions when applied to sewage disposal fields.

scholarly journals Aerobic Denitrifying Bacteria That Produce Low Levels of Nitrous Oxide

2003 ◽  
Vol 69 (6) ◽  
pp. 3152-3157 ◽  
Author(s):  
Naoki Takaya ◽  
Maria Antonina B. Catalan-Sakairi ◽  
Yasushi Sakaguchi ◽  
Isao Kato ◽  
Zhemin Zhou ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Paracoccus Denitrificans ◽  
Pseudomonas Stutzeri ◽  
Denitrifying Bacteria ◽  
Continuous Cultures ◽  
Aerobic Conditions ◽  
Stage Process ◽  
Low Levels ◽  
Microbial N

ABSTRACT Most denitrifiers produce nitrous oxide (N2O) instead of dinitrogen (N2) under aerobic conditions. We isolated and characterized novel aerobic denitrifiers that produce low levels of N2O under aerobic conditions. We monitored the denitrification activities of two of the isolates, strains TR2 and K50, in batch and continuous cultures. Both strains reduced nitrate (NO3 −) to N2 at rates of 0.9 and 0.03 μmol min−1 unit of optical density at 540 nm−1 at dissolved oxygen (O2) (DO) concentrations of 39 and 38 μmol liter−1, respectively. At the same DO level, the typical denitrifier Pseudomonas stutzeri and the previously described aerobic denitrifier Paracoccus denitrificans did not produce N2 but evolved more than 10-fold more N2O than strains TR2 and K50 evolved. The isolates denitrified NO3 − with concomitant consumption of O2. These results indicated that strains TR2 and K50 are aerobic denitrifiers. These two isolates were taxonomically placed in the β subclass of the class Proteobacteria and were identified as P. stutzeri TR2 and Pseudomonas sp. strain K50. These strains should be useful for future investigations of the mechanisms of denitrifying bacteria that regulate N2O emission, the single-stage process for nitrogen removal, and microbial N2O emission into the ecosystem.

Nature’s way of handling a greenhouse gas: the copper-sulfur cluster of purple nitrous oxide reductase

2012 ◽  
Vol 393 (10) ◽  
pp. 1067-1077 ◽  
Author(s):  
Anja Wüst ◽  
Lisa Schneider ◽  
Anja Pomowski ◽  
Walter G. Zumft ◽  
Peter M.H. Kroneck ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Paracoccus Denitrificans ◽  
Copper Ions ◽  
Bacterial Species ◽  
Three Dimensional ◽  
Pseudomonas Stutzeri ◽  
Structural Data ◽  
Nitrous Oxide Reductase ◽  
Bridging Ligand ◽  
Marinobacter Hydrocarbonoclasticus

Abstract The tetranuclear CuZ cluster is the unique active site of nitrous oxide reductase, the enzyme that catalyzes the reduction of nitrous oxide to dinitrogen as the final reaction in bacterial denitrification. Three-dimensional structures of orthologs of the enzyme from a variety of different bacterial species were essential steps in the elucidation of the properties of this center. However, while structural data first revealed and later confirmed the presence of four copper ions in spectroscopically distinct forms of CuZ, the exact structure and stoichiometry of the cluster showed significant variations. A ligand bridging ions CuZ1 and CuZ2 was initially assigned as a water or hydroxo species in the structures from Pseudomonas nautica (now Marinobacter hydrocarbonoclasticus) and Paracoccus denitrificans. This ligand was absent in a structure from ‘Achromobacter cycloclastes’, and could be reconstituted by iodide that acted as an inhibitor of catalysis. A recent structure of anoxically isolated nitrous oxide reductase from Pseudomonas stutzeri revealed the bridging ligand to be sulfide, S2-, and showed an unprecedented side-on mode of nitrous oxide binding to this form of CuZ.

scholarly journals Nitrification rates and associated nitrous oxide emissions from agricultural soils – a synopsis

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 469 ◽  
Author(s):  
Ryan Farquharson
Keyword(s):  
Nitrous Oxide ◽  
Water Content ◽  
Agricultural Soils ◽  
Strong Support ◽  
Specific Model ◽  
Nitrous Oxide Emissions ◽  
Ammonium Concentration ◽  
N2o Emissions ◽  
Site Specific ◽  
Aerobic Conditions

Laboratory incubations were performed to estimate nitrification rates and the associated nitrous oxide (N2O) emissions under aerobic conditions on a range of soils from National Agricultural Nitrous Oxide Research Program field sites. Significant site-to-site variability in nitrification rates and associated N2O emissions was observed under standardised conditions, indicating the need for site-specific model parameterisation. Generally, nitrification rates and N2O emissions increased with higher water content, ammonium concentration and temperature, although there were exceptions. It is recommended that site-specific model parameterisation be informed by such data. Importantly, the ratio of N2O emitted to net nitrified N under aerobic conditions was small (<0.2% for the majority of measurements) but did vary from 0.03% to 1%. Some models now include variation in the proportion of nitrified N emitted as N2O as a function of water content; however, strong support for this was not found across all of our experiments, and the results demonstrate a potential role of pH and ammonium availability. Further research into fluctuating oxygen availability and the coupling of biotic and abiotic processes will be required to progress the process understanding of N2O emissions from nitrification.

Effects of Straw Recycling of Winter Covering Crop on Methane and Nitrous Oxide Emissions in Paddy Field

2011 ◽  
Vol 37 (9) ◽  
pp. 1666-1675
Author(s):  
Hai-Ming TANG ◽  
Xiao-Ping XIAO ◽  
Wen-Guang TANG ◽  
Guang-Li YANG
Keyword(s):  
Nitrous Oxide ◽  
Paddy Field ◽  
Nitrous Oxide Emissions

scholarly journals Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Khadim Dawar ◽  
Shah Fahad ◽  
M. M. R. Jahangir ◽  
Iqbal Munir ◽  
Syed Sartaj Alam ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Grain Yield ◽  
Block Design ◽  
N Uptake ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Urease Inhibitor ◽  
Alkaline Soil ◽  
Total N ◽  
N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

scholarly journals Estimating Agricultural Nitrous Oxide Emissions

Eos ◽  
2008 ◽  
Vol 89 (51) ◽  
pp. 529 ◽  
Author(s):  
Stephen J. Del Grosso ◽  
Tom Wirth ◽  
Stephen M. Ogle ◽  
William J. Parton
Keyword(s):  
Nitrous Oxide ◽  
Nitrous Oxide Emissions
Sign in / Sign up

Export Citation Format

Share Document