scholarly journals Effects of Soil pH on Gaseous Nitrogen Loss Pathway via Feammox Process

2021 ◽  
Vol 13 (18) ◽  
pp. 10393
Author(s):  
Ding Ma ◽  
Jin Wang ◽  
Jun Xue ◽  
Zhengbo Yue ◽  
Shaofeng Xia ◽  
...  
Keyword(s):  
Soil Ph ◽  
Soil Acidification ◽  
Iron Reduction ◽  
Nitrogen Loss ◽  
Natural Environments ◽  
Ammonium Oxidation ◽  
N Loss ◽  
Molecular Biotechnology ◽  
Reducing Bacteria ◽  
Gaseous N Loss

The application of N fertilizer is one of the most critical soil acidification factors in China, and soil acidification significantly alters biogeochemical processes such as N loss. Anaerobic ammonium oxidation coupled with iron reduction (Feammox) is an important biological process for N loss in natural environments, with the end-products of N2, NO2− and NO3−. However, the response of Feammox pathways to soil pH fluctuation has not been thoroughly studied. In the current study, Feammox pathways and microbial communities were explored through a slurry culture experiment with an artificially adjusted pH combined with a 15N isotope tracing technique and molecular biotechnology. Results showed significant differences in the gaseous N loss through Feammox (0.42–0.97 mg N kg−1 d−1) under different pH conditions. The gaseous N loss pathways were significantly affected by the pH, and Feammox to N2 was the predominant pathway in low-pH incubations. The proportion of N loss caused by Feammox coupled with denitrification increased as the soil pH increased. The gaseous N loss through Feammox increased by 43.9% when the soil pH decreased from 6.5 to 5.0. Fe-reducing bacteria, such as Ochrobactrum, Sphingomonas, and Clostridium increased significantly in lower pH incubations. Overall, this study demonstrated the effects of soil pH on Feammox pathways and extended the understanding of the N biogeochemical cycle in acidic soil.

scholarly journals Nitrogen Loss through Anaerobic Ammonium Oxidation Coupled to Iron Reduction from Paddy Soils in a Chronosequence

2014 ◽  
Vol 48 (18) ◽  
pp. 10641-10647 ◽  
Author(s):  
Long-Jun Ding ◽  
Xin-Li An ◽  
Shun Li ◽  
Gan-Lin Zhang ◽  
Yong-Guan Zhu
Keyword(s):  
Iron Reduction ◽  
Nitrogen Loss ◽  
Anaerobic Ammonium Oxidation ◽  
Paddy Soils ◽  
Ammonium Oxidation

Nitrogen loss through anaerobic ammonium oxidation coupled with iron reduction in a mangrove wetland

2018 ◽  
Vol 69 (4) ◽  
pp. 732-741 ◽  
Author(s):  
Q. S. Guan ◽  
W. Z. Cao ◽  
M. Wang ◽  
G. J. Wu ◽  
F. F. Wang ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Nitrogen Loss ◽  
Anaerobic Ammonium Oxidation ◽  
Ammonium Oxidation ◽  
Mangrove Wetland

scholarly journals High denitrification and anaerobic ammonium oxidation contributes to net nitrogen loss in a seagrass ecosystem in the central Red Sea

2018 ◽  
Vol 15 (23) ◽  
pp. 7333-7346 ◽  
Author(s):  
Neus Garcias-Bonet ◽  
Marco Fusi ◽  
Muhammad Ali ◽  
Dario R. Shaw ◽  
Pascal E. Saikaly ◽  
...  
Keyword(s):  
Red Sea ◽  
Coastal Lagoon ◽  
N2 Fixation ◽  
Nitrogen Loss ◽  
Anaerobic Ammonium Oxidation ◽  
Ammonium Oxidation ◽  
N Loss ◽  
Seagrass Meadows ◽  
Bare Sediment ◽  
N Removal

Abstract. Nitrogen loads in coastal areas have increased dramatically, with detrimental consequences for coastal ecosystems. Shallow sediments and seagrass meadows are hotspots for denitrification, favoring N loss. However, atmospheric dinitrogen (N2) fixation has been reported to support seagrass growth. Therefore, the role of coastal marine systems dominated by seagrasses in the net N2 flux remains unclear. Here, we measured denitrification, anaerobic ammonium oxidation (anammox), and N2 fixation in a tropical seagrass (Enhalus acoroides) meadow and the adjacent bare sediment in a coastal lagoon in the central Red Sea. We detected high annual mean rates of denitrification (34.9±10.3 and 31.6±8.9 mg N m−2 d−1) and anammox (12.4±3.4 and 19.8±4.4 mg N m−2 d−1) in vegetated and bare sediments. The annual mean N loss was higher (between 8 and 63-fold) than the N2 fixed (annual mean = 5.9±0.2 and 0.8±0.3 mg N m−2 d−1) in the meadow and bare sediment, leading to a net flux of N2 from sediments to the atmosphere. Despite the importance of this coastal lagoon in removing N from the system, N2 fixation can contribute substantially to seagrass growth since N2 fixation rates found here could contribute up to 36 % of plant N requirements. In vegetated sediments, anammox rates decreased with increasing organic matter (OM) content, while N2 fixation increased with OM content. Denitrification and anammox increased linearly with temperature, while N2 fixation showed a maximum at intermediate temperatures. Therefore, the forecasted warming could further increase the N2 flux from sediments to the atmosphere, potentially impacting seagrass productivity and their capacity to mitigate climate change but also enhancing their potential N removal.

Anaerobic ammonium oxidation linked to sulfate and ferric iron reduction fuels nitrogen loss in marine sediments

2018 ◽  
Vol 29 (5) ◽  
pp. 429-442 ◽  
Author(s):  
E. Emilia Rios-Del Toro ◽  
Edgardo I. Valenzuela ◽  
Nguyen E. López-Lozano ◽  
M. Guadalupe Cortés-Martínez ◽  
Miguel A. Sánchez-Rodríguez ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Iron Reduction ◽  
Ferric Iron ◽  
Nitrogen Loss ◽  
Anaerobic Ammonium Oxidation ◽  
Ammonium Oxidation

scholarly journals Characterization of incubation experiments and development of an enrichment culture capable of ammonium oxidation under iron-reducing conditions

2015 ◽  
Vol 12 (3) ◽  
pp. 769-779 ◽  
Author(s):  
S. Huang ◽  
P. R. Jaffé
Keyword(s):  
Iron Reduction ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Enrichment Culture ◽  
Nitrogen Loss ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Ammonium Oxidation ◽  
Soil Slurry ◽  
Riparian Wetland ◽  
Incubation Experiments

Abstract. Incubation experiments were conducted using soil samples from a forested riparian wetland where we have previously observed anaerobic ammonium oxidation coupled to iron reduction. Production of both nitrite and ferrous iron was measured repeatedly during incubations when the soil slurry was supplied with either ferrihydrite or goethite and ammonium chloride. Significant changes in the microbial community were observed after 180 days of incubation as well as in a continuous flow membrane reactor, using 16S rRNA gene PCR-denaturing gradient gel electrophoresis, 454 pyrosequencing, and real-time quantitative PCR analysis. We be Acidimicrobiaceae bacterium A6), belonging to the Acidimicrobiaceae family, whose closest cultivated relative is Ferrimicrobium acidiphilum (with 92% identity) and Acidimicrobium ferrooxidans (with 90% identity), might play a key role in this anaerobic biological process that uses ferric iron as an electron acceptor while oxidizing ammonium to nitrite. After ammonium was oxidized to nitrite, nitrogen loss proceeded via denitrification and/or anammox.

Evidence of Nitrogen Loss from Anaerobic Ammonium Oxidation Coupled with Ferric Iron Reduction in an Intertidal Wetland

2015 ◽  
Vol 49 (19) ◽  
pp. 11560-11568 ◽  
Author(s):  
Xiaofei Li ◽  
Lijun Hou ◽  
Min Liu ◽  
Yanling Zheng ◽  
Guoyu Yin ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Ferric Iron ◽  
Nitrogen Loss ◽  
Anaerobic Ammonium Oxidation ◽  
Ammonium Oxidation ◽  
Intertidal Wetland

scholarly journals High denitrification and anaerobic ammonium oxidation contributes to net nitrogen loss in a seagrass ecosystem in the central Red Sea

2018 ◽  
Author(s):  
Neus Garcias-Bonet ◽  
Marco Fusi ◽  
Muhammad Ali ◽  
Dario R. Shaw ◽  
Pascal E. Saikaly ◽  
...  
Keyword(s):  
Red Sea ◽  
Coastal Lagoon ◽  
N2 Fixation ◽  
Nitrogen Loss ◽  
Anaerobic Ammonium Oxidation ◽  
Ammonium Oxidation ◽  
N Loss ◽  
Seagrass Meadows ◽  
Bare Sediment ◽  
N Removal

Abstract. Nitrogen loads in coastal areas have increased dramatically with detrimental consequences for coastal ecosystems. Shallow sediments and seagrass meadows are hotspots for denitrification, favoring N loss. However, atmospheric dinitrogen (N2) fixation has been reported to support seagrass growth. Therefore, the role of coastal marine systems dominated by seagrasses in the net N2 flux remains unclear. Here, we measured denitrification, anaerobic ammonium oxidation (anammox), and N2 fixation in tropical seagrass (Enhalus acoroides) meadow and the adjacent bare sediment in a coastal lagoon in the central Red Sea. We detected high annual mean rates of denitrification (34.9 ± 10.3 and 31.6 ± 8.9 mg N m−2 d−1) and anammox (12.4 ± 3.4 and 19.8 ± 4.4 mg N m−2 d−1) in vegetated and bare sediments. The annual mean N loss was higher (8 and 63-fold higher) than the N2 fixed (annual mean = 5.9 ± 0.2 and 0.8  ± 0.3 mg N m−2 d−1) in the meadow and bare sediment, leading to a net flux of N2 from sediments to the atmosphere. Despite the importance of this coastal lagoon in removing N from the system, N2 fixation can contribute substantially to seagrass growth since N2 fixation rates found here could contribute up to 36 % of plant N requirements. In vegetated sediments, anammox rates decreased with increasing organic matter (OM) content, while N2 fixation increased with OM content. Denitrification and anammox increased linearly with temperature, while N2 fixation showed a maximum at intermediate temperatures. Therefore, the forecasted warming could further increase the N2 flux from sediments to the atmosphere, potentially impacting seagrass productivity and their capacity to mitigate climate change but also enhancing their potential N removal.

scholarly journals Iron-reducing - and -proteobacteria isolated from laboratory-scaled heterotrophic feammox bioreactor

2021 ◽  
Vol 19 (2) ◽  
pp. 359-369
Author(s):  
Le Phuong Chung ◽  
Nguyen Thi Hai ◽  
Nguyen Huynh Minh Quyen ◽  
Pham The Hai ◽  
Dinh Thuy Hang
Keyword(s):  
16S Rdna ◽  
Iron Reduction ◽  
Ferric Iron ◽  
Nitrogen Loss ◽  
Pseudomonas Stutzeri ◽  
Ammonium Oxidation ◽  
Bacterial Strains ◽  
Ammonium Removal ◽  
Rdna Sequences ◽  
16S Rdna Sequences

Ammonium removal from wastewater is a crucial step in wastewater treatment. Presently employed technologies based on nitrification/denitrification and partial nitritation/anammox principles require oxygen for the nitrification step, and are therefore still not yet fully satisfied with the application practice. In recent years, biological ammonium oxidation coupled with ferric iron reduction (feammox) has been proposed to be responsible for the nitrogen loss in different ecological habitats. Related to the wastewater aspect, the feammox principle has been discussed as an alternative approach for ammonium removal without dependency on oxygen. From a laboratory-scaled feammox bioreactor operated under neutral pH, two bacterial strains FN7 and FN9 were isolated by using the anaerobic Hungate technique. Comparative analyses of 16S rDNA sequences showed that these strains were most closely related to the b-proteobacterium Aciclyphilus denitrificans and the g-proteobacterium Pseudomonas stutzeri, respectively. Although being phylogenetically apart, strains FN7 and FN9 shared several common physiological characteristics that are considered meaningful for the feammox process, i.e. (i) heteroptrophic ammonium oxidation, (ii) denitrification, and (iii) ferric iron reduction. These isolates are proposed to play certain roles in the studied feammox system, contributing to the ammonium removal under heterotrophic feammox condition. The 16S rDNA sequences of strains FN7 and FN9 were available in GenBank under the accession numbers LC474369 and MT568614, respectively.

scholarly journals Electrode Colonization by the Feammox Bacterium Acidimicrobiaceae sp. Strain A6

2018 ◽  
Vol 84 (24) ◽  
Author(s):  
Melany Ruiz-Urigüen ◽  
Weitao Shuai ◽  
Peter R. Jaffé
Keyword(s):  
Iron Reduction ◽  
Electrical Current ◽  
Ammonium Oxidation ◽  
Riparian Wetland ◽  
Microbial Electrolysis Cells ◽  
Electrogenic Bacteria ◽  
Potential Electrode ◽  
Electrolysis Cells ◽  
Current Production ◽  
Reducing Bacteria

ABSTRACT Acidimicrobiaceae sp. strain A6 (A6), from the Actinobacteria phylum, was recently identified as a microorganism that can carry out anaerobic ammonium (NH4+) oxidation coupled to iron reduction, a process also known as Feammox. Being an iron-reducing bacterium, A6 was studied as a potential electrode-reducing bacterium that may transfer electrons extracellularly onto electrodes while gaining energy from NH4+ oxidation. Actinobacteria species have been overlooked as electrogenic bacteria, and the importance of lithoautotrophic iron reducers as electrode-reducing bacteria at anodes has not been addressed. By installing electrodes in the soil of a forested riparian wetland where A6 thrives, in soil columns in the laboratory, and in A6-bioaugmented constructed wetland (CW) mesocosms and by operating microbial electrolysis cells (MECs) with pure A6 culture, the characteristics and performances of this organism as an electrode-reducing bacterium candidate were investigated. In this study, we show that Acidimicrobiaceae sp. strain A6, a lithoautotrophic bacterium, is capable of colonizing electrodes under controlled conditions. In addition, A6 appears to be an electrode-reducing bacterium, since current production was boosted shortly after the CWs were seeded with enrichment A6 culture and current production was detected in MECs operated with pure A6, with the anode as the sole electron acceptor and NH4+ as the sole electron donor. IMPORTANCE Most studies on electrogenic microorganisms have focused on the most abundant heterotrophs, while other microorganisms also commonly present in electrode microbial communities, such as Actinobacteria strains, have been overlooked. The novel Acidimicrobiaceae sp. strain A6 (Actinobacteria) is an iron-reducing bacterium that can colonize the surface of anodes in sediments and is linked to electrical current production, making it an electrode-reducing bacterium. Furthermore, A6 can carry out anaerobic ammonium oxidation coupled to iron reduction. Therefore, findings from this study open the possibility of using electrodes instead of iron as electron acceptors, as a means to promote A6 to treat NH4+-containing wastewater more efficiently. Altogether, this study expands our knowledge of electrogenic bacteria and opens the possibility of developing Feammox-based technologies coupled to bioelectric systems for the treatment of NH4+ and other contaminants in anoxic systems.

scholarly journals Characterization of incubation experiments and development of an enrichment culture capable of ammonium oxidation under iron reducing conditions

2014 ◽  
Vol 11 (8) ◽  
pp. 12295-12321 ◽  
Author(s):  
S. Huang ◽  
P. R. Jaffé
Keyword(s):  
Iron Reduction ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Enrichment Culture ◽  
Nitrogen Loss ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Ammonium Oxidation ◽  
Soil Slurry ◽  
Riparian Wetland ◽  
Incubation Experiments

Abstract. Incubation experiments were conducted using soil samples from a forested riparian wetland where we have previously observed anaerobic ammonium oxidation coupled to iron reduction. Production of both nitrite and ferrous iron were measured repeatedly during incubations when the soil slurry was supplied with either ferrihydrite or goethite and ammonium chloride. Significant changes in the microbial community were observed after 180 days of incubation as well as in a continuous flow membrane reactor, using 16S rRNA gene PCR-denaturing gradient gel electrophoresis, 454-pyrosequencing, and real-time quantitative PCR analysis. We believe that one of the dominant microbial species in our system (an uncultured Acidimicrobiaceae bacterium A6), belonging to the Acidimicrobiaceae family, whose closest cultivated relative is Ferrimicrobium acidiphilum (with 92% identity) and Acidimicrobium ferrooxidans (with 90% identity), might play a key role in this anaerobic biological process that uses ferric iron as an electron acceptor while oxidizing ammonium to nitrite. After ammonium was oxidized to nitrite, nitrogen loss proceeded via denitrification and/or anammox.

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