Interactions and responses of n-damo archaea, n-damo bacteria and anammox bacteria to various electron acceptors in natural and constructed wetland sediments

2019 ◽  
Vol 144 ◽  
pp. 104749
Author(s):  
Yong-Feng Wang ◽  
Richard P. Dick ◽  
Nicola Lorenz ◽  
Nathan Lee
Keyword(s):  
Constructed Wetland ◽  
Electron Acceptors ◽  
Anammox Bacteria ◽  
Damo Bacteria

scholarly journals Simultaneous Nitrite-Dependent Anaerobic Methane and Ammonium Oxidation Processes

2011 ◽  
Vol 77 (19) ◽  
pp. 6802-6807 ◽  
Author(s):  
Francisca A. Luesken ◽  
Jaime Sánchez ◽  
Theo A. van Alen ◽  
Janeth Sanabria ◽  
Huub J. M. Op den Camp ◽  
...  
Keyword(s):  
Enrichment Culture ◽  
Anammox Bacteria ◽  
Anaerobic Oxidation Of Methane ◽  
Ammonium Oxidation ◽  
Content Type ◽  
Oxidation Of Methane ◽  
Activity Measurements ◽  
Near Future ◽  
Damo Bacteria

ABSTRACTNitrite-dependent anaerobic oxidation of methane (n-damo) and ammonium (anammox) are two recently discovered processes in the nitrogen cycle that are catalyzed by n-damo bacteria, including “CandidatusMethylomirabilis oxyfera,” and anammox bacteria, respectively. The feasibility of coculturing anammox and n-damo bacteria is important for implementation in wastewater treatment systems that contain substantial amounts of both methane and ammonium. Here we tested this possible coexistence experimentally. To obtain such a coculture, ammonium was fed to a stable enrichment culture of n-damo bacteria that still contained some residual anammox bacteria. The ammonium supplied to the reactor was consumed rapidly and could be gradually increased from 1 to 20 mM/day. The enriched coculture was monitored by fluorescencein situhybridization and 16S rRNA andpmoAgene clone libraries and activity measurements. After 161 days, a coculture with about equal amounts of n-damo and anammox bacteria was established that converted nitrite at a rate of 0.1 kg-N/m3/day (17.2 mmol day−1). This indicated that the application of such a coculture for nitrogen removal may be feasible in the near future.

scholarly journals Community Composition and Spatial Distribution of N-Removing Microorganisms Optimized by Fe-Modified Biochar in a Constructed Wetland

2021 ◽  
Vol 18 (6) ◽  
pp. 2938
Author(s):  
Wen Jia ◽  
Liuyan Yang
Keyword(s):  
Spatial Distribution ◽  
Constructed Wetland ◽  
Treatment Plant ◽  
Anammox Bacteria ◽  
Spatial Distributions ◽  
Ammonium Oxidation ◽  
Community Structures ◽  
Modified Biochar ◽  
N Removal ◽  
Microbial Nitrogen

Microbial nitrogen (N) removal capability can be significantly enhanced in a horizontal subsurface flow constructed wetland (HSCW) amended by Fe-modified biochar (FeB). To further explore the microbiological mechanism of FeB enhancing N removal, nirS- and nirK-denitrifier community diversities, as well as spatial distributions of denitrifiers and anaerobic ammonium oxidation (anammox) bacteria, were investigated in HSCWs (C-HSCW: without biochar and FeB; B-HSCW: amended by biochar; FeB-HSCW: amended by FeB) treating tailwater from a wastewater treatment plant, with C-HSCW without biochar and FeB and B-HSCW amended by biochar as control. The community structures of nirS- and nirK-denitrifiers in FeB-HSCW were significantly optimized for improved N removal compared with the two other HSCWs, although no significant differences in their richness and diversity were detected among the HSCWs. The spatial distributions of the relative abundance of genes involved in denitrification and anammox were more heterogeneous and complex in FeB-HSCW than those in other HSCWs. More and larger high-value patches were observed in FeB-HSCW. These revealed that FeB provides more appropriate habitats for N-removing microorganisms, which can prompt the bacteria to use the habitats more differentially, without competitive exclusion. Overall, the Fe-modified biochar enhancement of the microbial N-removal capability of HSCWs was a result of optimized microbial community structures, higher functional gene abundance, and improved spatial distribution of N-removing microorganisms.

scholarly journals Extracellular electron transfer-dependent anaerobic oxidation of ammonium by anammox bacteria

2019 ◽  
Author(s):  
Dario R. Shaw ◽  
Muhammad Ali ◽  
Krishna P. Katuri ◽  
Jeffrey A. Gralnick ◽  
Joachim Reimann ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Acceptor ◽  
Electron Acceptors ◽  
Extracellular Electron Transfer ◽  
Anammox Bacteria ◽  
Significant Finding ◽  
Ammonium Oxidation ◽  
Anaerobic Oxidation ◽  
Terminal Electron Acceptor ◽  
Carbon Based

AbstractAnaerobic ammonium oxidation (anammox) by anammox bacteria contributes significantly to the global nitrogen cycle, and plays a major role in sustainable wastewater treatment. Anammox bacteria convert ammonium (NH4+) to dinitrogen gas (N2) using nitrite (NO2−) or nitric oxide (NO) as the electron acceptor. In the absence of NO2− or NO, anammox bacteria can couple formate oxidation to the reduction of metal oxides such as Fe(III) or Mn(IV). Their genomes contain homologs of Geobacter and Shewanella cytochromes involved in extracellular electron transfer (EET). However, it is still unknown whether anammox bacteria have EET capability and can couple the oxidation of NH4+ with transfer of electrons to carbon-based insoluble extracellular electron acceptors. Here we show using complementary approaches that in the absence of NO2−, freshwater and marine anammox bacteria couple the oxidation of NH4+ with transfer of electrons to carbon-based insoluble extracellular electron acceptors such as graphene oxide (GO) or electrodes poised at a certain potential in microbial electrolysis cells (MECs). Metagenomics, fluorescence in-situ hybridization and electrochemical analyses coupled with MEC performance confirmed that anammox electrode biofilms were responsible for current generation through EET-dependent oxidation of NH4+. 15N-labelling experiments revealed the molecular mechanism of the EET-dependent anammox process. NH4+ was oxidized to N2 via hydroxylamine (NH2OH) as intermediate when electrode was the terminal electron acceptor. Comparative transcriptomics analysis supported isotope labelling experiments and revealed an alternative pathway for NH4+ oxidation coupled to EET when electrode is used as electron acceptor compared to NO2−as electron acceptor. To our knowledge, our results provide the first experimental evidence that marine and freshwater anammox bacteria can couple NH4+ oxidation with EET, which is a significant finding, and challenges our perception of a key player of anaerobic oxidation of NH4+ in natural environments and engineered systems.

scholarly journals Evidence for the Cooccurrence of Nitrite-Dependent Anaerobic Ammonium and Methane Oxidation Processes in a Flooded Paddy Field

2014 ◽  
Vol 80 (24) ◽  
pp. 7611-7619 ◽  
Author(s):  
Li-dong Shen ◽  
Shuai Liu ◽  
Qian Huang ◽  
Xu Lian ◽  
Zhan-fei He ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Paddy Field ◽  
Dry Weight ◽  
Anammox Bacteria ◽  
Wetland Soils ◽  
Soil Cores ◽  
Ammonium Oxidation ◽  
Content Type ◽  
Oxidation Rates ◽  
Damo Bacteria

ABSTRACTAnaerobic ammonium oxidation (anammox) and nitrite-dependent anaerobic methane oxidation (n-damo) are two of the most recent discoveries in the microbial nitrogen cycle. In the present study, we provide direct evidence for the cooccurrence of the anammox and n-damo processes in a flooded paddy field in southeastern China. Stable isotope experiments showed that the potential anammox rates ranged from 5.6 to 22.7 nmol N2g−1(dry weight) day−1and the potential n-damo rates varied from 0.2 to 2.1 nmol CO2g−1(dry weight) day−1in different layers of soil cores. Quantitative PCR showed that the abundance of anammox bacteria ranged from 1.0 × 105to 2.0 × 106copies g−1(dry weight) in different layers of soil cores and the abundance of n-damo bacteria varied from 3.8 × 105to 6.1 × 106copies g−1(dry weight). Phylogenetic analyses of the recovered 16S rRNA gene sequences showed that anammox bacteria affiliated with “CandidatusBrocadia” and “CandidatusKuenenia” and n-damo bacteria related to “CandidatusMethylomirabilis oxyfera” were present in the soil cores. It is estimated that a total loss of 50.7 g N m−2per year could be linked to the anammox process, which is at intermediate levels for the nitrogen flux ranges of aerobic ammonium oxidation and denitrification reported in wetland soils. In addition, it is estimated that a total of 0.14 g CH4m−2per year could be oxidized via the n-damo process, while this rate is at the lower end of the aerobic methane oxidation rates reported in wetland soils.

Distribution of anammox bacteria in a free-water-surface constructed wetland with wild rice (Zizania latifolia)

2015 ◽  
Vol 81 ◽  
pp. 165-172 ◽  
Author(s):  
Miyoko Waki ◽  
Tomoko Yasuda ◽  
Kazuyoshi Suzuki ◽  
Michio Komada ◽  
Kaoru Abe
Keyword(s):  
Constructed Wetland ◽  
Wild Rice ◽  
Water Surface ◽  
Free Water ◽  
Anammox Bacteria ◽  
Zizania Latifolia ◽  
Free Water Surface

Electronic structure studies of conducting polymers by electron energy-loss spectroscopy

1996 ◽  
Vol 54 ◽  
pp. 160-161
Author(s):  
J. Fink
Keyword(s):  
Electronic Structure ◽  
Conducting Polymers ◽  
Conjugated Polymers ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Light Emitting ◽  
One Dimensional ◽  
New Class ◽  
Electrical Conductivities ◽  
Electron Energy Loss

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

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