scholarly journals Spatial Distribution and Factors Shaping the Niche Segregation of Ammonia-Oxidizing Microorganisms in the Qiantang River, China

2013 ◽  
Vol 79 (13) ◽  
pp. 4065-4071 ◽  
Author(s):  
Shuai Liu ◽  
Lidong Shen ◽  
Liping Lou ◽  
Guangming Tian ◽  
Ping Zheng ◽  
...  

ABSTRACTAmmonia oxidation is performed by both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). However, the current knowledge of the distribution, diversity, and relative abundance of these two microbial groups in freshwater sediments is insufficient. We examined the spatial distribution and analyzed the possible factors leading to the niche segregation of AOA and AOB in the sediments of the Qiantang River, using clone library construction and quantitative PCR for both archaeal and bacterialamoAgenes. pH and NH4+-N content had a significant effect on AOA abundance and AOA operational taxonomy unit (OTU) numbers. pH and organic carbon content influenced the ratio of AOA/AOB OTU numbers significantly. The influence of these factors showed an obvious spatial trend along the Qiantang River. This result suggested that AOA may contribute more than AOB to the upstream reaches of the Qiantang River, where the pH is lower and the organic carbon and NH4+-N contents are higher, but AOB were the principal driver of nitrification downstream, where the opposite environmental conditions were present.

2021 ◽  
Vol 13 (15) ◽  
pp. 8332
Author(s):  
Snežana Jakšić ◽  
Jordana Ninkov ◽  
Stanko Milić ◽  
Jovica Vasin ◽  
Milorad Živanov ◽  
...  

Topography-induced microclimate differences determine the local spatial variation of soil characteristics as topographic factors may play the most essential role in changing the climatic pattern. The aim of this study was to investigate the spatial distribution of soil organic carbon (SOC) with respect to the slope gradient and aspect, and to quantify their influence on SOC within different land use/cover classes. The study area is the Region of Niš in Serbia, which is characterized by complex topography with large variability in the spatial distribution of SOC. Soil samples at 0–30 cm and 30–60 cm were collected from different slope gradients and aspects in each of the three land use/cover classes. The results showed that the slope aspect significantly influenced the spatial distribution of SOC in the forest and vineyard soils, where N- and NW-facing soils had the highest level of organic carbon in the topsoil. There were no similar patterns in the uncultivated land. No significant differences were found in the subsoil. Organic carbon content was higher in the topsoil, regardless of the slope of the terrain. The mean SOC content in forest land decreased with increasing slope, but the difference was not statistically significant. In vineyards and uncultivated land, the SOC content was not predominantly determined by the slope gradient. No significant variations across slope gradients were found for all observed soil properties, except for available phosphorus and potassium. A positive correlation was observed between SOC and total nitrogen, clay, silt, and available phosphorus and potassium, while a negative correlation with coarse sand was detected. The slope aspect in relation to different land use/cover classes could provide an important reference for land management strategies in light of sustainable development.


2013 ◽  
Vol 10 (11) ◽  
pp. 7395-7410 ◽  
Author(s):  
A. E. Santoro ◽  
C. M. Sakamoto ◽  
J. M. Smith ◽  
J. N. Plant ◽  
A. L. Gehman ◽  
...  

Abstract. Nitrite (NO2−) is a substrate for both oxidative and reductive microbial metabolism. NO2− accumulates at the base of the euphotic zone in oxygenated, stratified open-ocean water columns, forming a feature known as the primary nitrite maximum (PNM). Potential pathways of NO2− production include the oxidation of ammonia (NH3) by ammonia-oxidizing bacteria and archaea as well as assimilatory nitrate (NO3−) reduction by phytoplankton and heterotrophic bacteria. Measurements of NH3 oxidation and NO3− reduction to NO2− were conducted at two stations in the central California Current in the eastern North Pacific to determine the relative contributions of these processes to NO2− production in the PNM. Sensitive (< 10 nmol L−1), precise measurements of [NH4+] and [NO2−] indicated a persistent NH4+ maximum overlying the PNM at every station, with concentrations as high as 1.5 μmol L−1. Within and just below the PNM, NH3 oxidation was the dominant NO2− producing process, with rates of NH3 oxidation to NO2− of up to 31 nmol L−1 d−1, coinciding with high abundances of ammonia-oxidizing archaea. Though little NO2− production from NO3− was detected, potentially nitrate-reducing phytoplankton (photosynthetic picoeukaryotes, Synechococcus, and Prochlorococcus) were present at the depth of the PNM. Rates of NO2− production from NO3− were highest within the upper mixed layer (4.6 nmol L−1 d−1) but were either below detection limits or 10 times lower than NH3 oxidation rates around the PNM. One-dimensional modeling of water column NO2− production agreed with production determined from 15N bottle incubations within the PNM, but a modeled net biological sink for NO2− just below the PNM was not captured in the incubations. Residence time estimates of NO2− within the PNM ranged from 18 to 470 days at the mesotrophic station and was 40 days at the oligotrophic station. Our results suggest the PNM is a dynamic, rather than relict, feature with a source term dominated by ammonia oxidation.


Science ◽  
2011 ◽  
Vol 333 (6047) ◽  
pp. 1282-1285 ◽  
Author(s):  
Alyson E. Santoro ◽  
Carolyn Buchwald ◽  
Matthew R. McIlvin ◽  
Karen L. Casciotti

The ocean is an important global source of nitrous oxide (N2O), a greenhouse gas that contributes to stratospheric ozone destruction. Bacterial nitrification and denitrification are thought to be the primary sources of marine N2O, but the isotopic signatures of N2O produced by these processes are not consistent with the marine contribution to the global N2O budget. Based on enrichment cultures, we report that archaeal ammonia oxidation also produces N2O. Natural-abundance stable isotope measurements indicate that the produced N2O had bulk δ15N and δ18O values higher than observed for ammonia-oxidizing bacteria but similar to the δ15N and δ18O values attributed to the oceanic N2O source to the atmosphere. Our results suggest that ammonia-oxidizing archaea may be largely responsible for the oceanic N2O source.


2012 ◽  
Vol 78 (16) ◽  
pp. 5773-5780 ◽  
Author(s):  
Elizabeth French ◽  
Jessica A. Kozlowski ◽  
Maitreyee Mukherjee ◽  
George Bullerjahn ◽  
Annette Bollmann

ABSTRACTAerobic biological ammonia oxidation is carried out by two groups of microorganisms, ammonia-oxidizing bacteria (AOB) and the recently discovered ammonia-oxidizing archaea (AOA). Here we present a study using cultivation-based methods to investigate the differences in growth of three AOA cultures and one AOB culture enriched from freshwater environments. The strain in the enriched AOA culture belong to thaumarchaeal group I.1a, with the strain in one enrichment culture having the highest identity with “CandidatusNitrosoarchaeum koreensis” and the strains in the other two representing a new genus of AOA. The AOB strain in the enrichment culture was also obtained from freshwater and had the highest identity to AOB from theNitrosomonas oligotrophagroup (Nitrosomonascluster 6a). We investigated the influence of ammonium, oxygen, pH, and light on the growth of AOA and AOB. The growth rates of the AOB increased with increasing ammonium concentrations, while the growth rates of the AOA decreased slightly. Increasing oxygen concentrations led to an increase in the growth rate of the AOB, while the growth rates of AOA were almost oxygen insensitive. Light exposure (white and blue wavelengths) inhibited the growth of AOA completely, and the AOA did not recover when transferred to the dark. AOB were also inhibited by blue light; however, growth recovered immediately after transfer to the dark. Our results show that the tested AOB have a competitive advantage over the tested AOA under most conditions investigated. Further experiments will elucidate the niches of AOA and AOB in more detail.


2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Yun-Feng Duan ◽  
Xian-Wang Kong ◽  
Andreas Schramm ◽  
Rodrigo Labouriau ◽  
Jørgen Eriksen ◽  
...  

ABSTRACT Grassland cultivation can mobilize large pools of N in the soil, with the potential for N leaching and N2O emissions. Spraying with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) before cultivation was simulated by use of soil columns in which the residue distribution corresponded to plowing or rotovation to study the effects of soil-residue contact on N transformations. DMPP was sprayed on aboveground parts of ryegrass and white clover plants before incorporation. During a 42-day incubation, soil mineral N dynamics, potential ammonia oxidation (PAO), denitrifying enzyme activity (DEA), nitrifier and denitrifier populations, and N2O emissions were investigated. The soil NO3 − pool was enriched with 15N to trace sources of N2O. Ammonium was rapidly released from decomposing residues, and PAO was stimulated in soil near residues. DMPP effectively reduced NH4 + transformation irrespective of residue distribution. Ammonia-oxidizing archaea (AOA) and bacteria (AOB) were both present, but only the AOB amoA transcript abundance correlated with PAO. DMPP inhibited the transcription of AOB amoA genes. Denitrifier genes and transcripts (nirK, nirS, and clades I and II of nosZ) were recovered, and a correlation was found between nirS mRNA and DEA. DMPP showed no adverse effects on the abundance or activity of denitrifiers. The 15N enrichment of N2O showed that denitrification was responsible for 80 to 90% of emissions. With support from a control experiment without NO3 − amendment, it was concluded that DMPP will generally reduce the potential for leaching of residue-derived N, whereas the effect of DMPP on N2O emissions will be significant only when soil NO3 − availability is limiting. IMPORTANCE Residue incorporation following grassland cultivation can lead to mobilization of large pools of N and potentially to significant N losses via leaching and N2O emissions. This study proposed a mitigation strategy of applying 3,4-dimethylpyrazole phosphate (DMPP) prior to grassland cultivation and investigated its efficacy in a laboratory incubation study. DMPP inhibited the growth and activity of ammonia-oxidizing bacteria but had no adverse effects on ammonia-oxidizing archaea and denitrifiers. DMPP can effectively reduce the potential for leaching of NO3 − derived from residue decomposition, while the effect on reducing N2O emissions will be significant only when soil NO3 − availability is limiting. Our findings provide insight into how DMPP affects soil nitrifier and denitrifier populations and have direct implications for improving N use efficiency and reducing environmental impacts during grassland cultivation.


2020 ◽  
Vol 11 ◽  
Author(s):  
João Pereira Santos ◽  
António G. G. Sousa ◽  
Hugo Ribeiro ◽  
Catarina Magalhães

Aerobic nitrification is a fundamental nitrogen biogeochemical process that links the oxidation of ammonia to the removal of fixed nitrogen in eutrophicated water bodies. However, in estuarine environments there is an enormous variability of water physicochemical parameters that can affect the ammonia oxidation biological process. For instance, it is known that salinity can affect nitrification performance, yet there is still a lack of information on the ammonia-oxidizing communities behavior facing daily salinity fluctuations. In this work, laboratory experiments using upstream and downstream estuarine sediments were performed to address this missing gap by comparing the effect of daily salinity fluctuations with constant salinity on the activity and diversity of ammonia-oxidizing microorganisms (AOM). Activity and composition of AOM were assessed, respectively by using nitrogen stable isotope technique and 16S rRNA gene metabarcoding analysis. Nitrification activity was negatively affected by daily salinity fluctuations in upstream sediments while no effect was observed in downstream sediments. Constant salinity regime showed clearly higher rates of nitrification in upstream sediments while a similar nitrification performance between the two salinity regimes was registered in the downstream sediments. Results also indicated that daily salinity fluctuation regime had a negative effect on both ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) community’s diversity. Phylogenetically, the estuarine downstream AOM were dominated by AOA (0.92–2.09%) followed by NOB (0.99–2%), and then AOB (0.2–0.32%); whereas NOB dominated estuarine upstream sediment samples (1.4–9.5%), followed by AOA (0.27–0.51%) and AOB (0.01–0.23%). Analysis of variance identified the spatial difference between samples (downstream and upstream) as the main drivers of AOA and AOB diversity. Our study indicates that benthic AOM inhabiting different estuarine sites presented distinct plasticity toward the salinity regimes tested. These findings help to improve our understanding in the dynamics of the nitrogen cycle of estuarine systems by showing the resilience and consequently the impact of different salinity regimes on the diversity and activity of ammonia oxidizer communities.


Soil Research ◽  
2010 ◽  
Vol 48 (1) ◽  
pp. 27 ◽  
Author(s):  
Masoomeh Delbari ◽  
Willibald Loiskandl ◽  
Peyman Afrasiab

Soil organic carbon (SOC) affects many processes in soil. The main objective of this study was the prediction and uncertainty assessment of the spatial patterns of SOC through stochastic simulation using 2 simulation algorithms, sequential Gaussian simulation (sGs) and sequential indicator simulation (sis). The dataset consisted of 158 point measurements of surface SOC taken from an 18-ha field in Lower Austria. Conditional stochastic simulation algorithms were used to generate 100 maps of equiprobable spatial distribution for SOC. In general the simulated maps represented spatial distribution of SOC more realistically than the kriged map, i.e. overcoming the smoothing effect of kriging. Unlike sGs, sis was able to preserve the connectivity of extreme values in generated maps. The SOC simulated maps generated through sGs reproduced the sample statistics well. The reproduction of class-specific patterns of spatial continuity of SOC for the simulated model produced through sis was also reasonably good. The results highlight that when the class-specific patterns of spatial continuity of the attribute must be preserved, sis is preferred to sGs. For local uncertainty, standard deviations obtained using kriging varied much less across the study area than those obtained using simulations. This shows that the conditional standard deviations achieved through simulations depend on data values in addition to data configuration for greater reliability in reporting the estimation precision. Further, according to accuracy plots and goodness statistic, G, sis performs the modelling uncertainty better than sGs. The simulated models can provide useful information in risk assessment of SOC management in Lower Austria.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 562
Author(s):  
Mehdi Sharif Shourjeh ◽  
Przemysław Kowal ◽  
Xi Lu ◽  
Li Xie ◽  
Jakub Drewnowski

Novel technologies such as partial nitritation (PN) and partial denitritation (PDN) could be combined with the anammox-based process in order to alleviate energy input. The former combination, also noted as deammonification, has been intensively studied in a frame of lab and full-scale wastewater treatment in order to optimize operational costs and process efficiency. For the deammonification process, key functional microbes include ammonia-oxidizing bacteria (AOB) and anaerobic ammonia oxidation bacteria (AnAOB), which coexisting and interact with heterotrophs and nitrite oxidizing bacteria (NOB). The aim of the presented review was to summarize current knowledge about deammonification process principles, related to microbial interactions responsible for the process maintenance under varying operational conditions. Particular attention was paid to the factors influencing the targeted selection of AOB/AnAOB over the NOB and application of the mathematical modeling as a powerful tool enabling accelerated process optimization and characterization. Another reviewed aspect was the potential energetic and resources savings connected with deammonification application in relation to the technologies based on the conventional nitrification/denitrification processes.


2021 ◽  
Author(s):  
Man-Young Jung ◽  
Christopher J. Sedlacek ◽  
K. Dimitri Kits ◽  
Anna J. Mueller ◽  
Sung-Keun Rhee ◽  
...  

AbstractNitrification, the oxidation of ammonia to nitrate, is an essential process in the biogeochemical nitrogen cycle. The first step of nitrification, ammonia oxidation, is performed by three, often co- occurring guilds of chemolithoautotrophs: ammonia-oxidizing bacteria (AOB), archaea (AOA), and complete ammonia oxidizers (comammox). Substrate kinetics are considered to be a major niche-differentiating factor between these guilds, but few AOA strains have been kinetically characterized. Here, the ammonia oxidation kinetic properties of 12 AOA representing all major phylogenetic lineages were determined using microrespirometry. Members of the genus Nitrosocosmicus have the lowest substrate affinity of any characterized AOA, which are similar to previously determined affinities of AOB. This contrasts previous assumptions that all AOA possess much higher substrate affinities than their comammox or AOB counterparts. The substrate affinity of ammonia oxidizers correlated with their cell surface area to volume ratios. In addition, kinetic measurements across a range of pH values strongly supports the hypothesis that – like for AOB – ammonia and not ammonium is the substrate for the ammonia monooxygenase enzyme of AOA and comammox. Together, these data will facilitate predictions and interpretation of ammonia oxidizer community structures and provide a robust basis for establishing testable hypotheses on competition between AOB, AOA, and comammox.


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