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Bioresource Technology May 2020Application of the modern microbial techniques changed the paradigm about the microorganisms performing nitrification. Numerous investigations recognized representatives... (Meta-Analysis)
Meta-Analysis Review
Application of the modern microbial techniques changed the paradigm about the microorganisms performing nitrification. Numerous investigations recognized representatives of the genus Nitrospira as a key and predominant nitrite-oxidizing bacteria in biological nutrient removal systems, especially under low dissolved oxygen and substrate conditions. The recent discovery of Nitrospira capable of performing complete ammonia oxidation (comammox) raised a fundamental question about the actual role of Nitrospira in both nitrification steps. This review summarizes the current knowledge about morphological, physiological and genetic characteristics of the canonical and comammox Nitrospira. Potential implications of comammox for the functional aspects of nitrogen removal have been highlighted. The complex meta-analysis of literature data was applied to identify specific individual variables and their combined interactions on the Nitrospira abundance. In addition to dissolved oxygen and influent nitrogen concentrations, temperature and pH may play an important role in enhancing or suppressing the Nitrospira activity.
Topics: Ammonia; Bacteria; Denitrification; Nitrification; Nitrites; Nitrogen; Oxidation-Reduction
PubMed: 32059161
DOI: 10.1016/j.biortech.2020.122936 -
Microbes and Environments 2020Biofilm carriers have been used to remove ammonia in several wastewater treatment plants (WWTPs) in Japan. However, the abundance and species of ammonia oxidizers in the...
Biofilm carriers have been used to remove ammonia in several wastewater treatment plants (WWTPs) in Japan. However, the abundance and species of ammonia oxidizers in the biofilms formed on the surface of carriers in full-scale operational WWTP tanks remain unclear. In the present study, we conducted quantitative PCR and PCR cloning of the amoA genes of ammonia-oxidizing bacteria and archaea (AOB and AOA) and a complete ammonia oxidizer (comammox) in the biofilm formed on the carriers in a full-scale WWTP. The quantification of amoA genes showed that the abundance of AOB and comammox was markedly greater in the biofilm than in the activated sludge suspended in a tank solution of the WWTP, while AOA was not detected in the biofilm or the activated sludge. A phylogenetic analysis of amoA genes revealed that as-yet-uncultivated comammox Nitrospira and uncultured AOB Nitrosomonas were predominant in the biofilm. The present results suggest that the biofilm formed on the surface of carriers enable comammox Nitrospira and AOB Nitrosomonas to co-exist and remain in the full-scale WWTP tank surveyed in this study.
Topics: Ammonia; Archaea; Bacteria; Biofilms; Japan; Nitrification; Oxidation-Reduction; Phylogeny; Waste Disposal, Fluid; Wastewater
PubMed: 32249239
DOI: 10.1264/jsme2.ME19140 -
STAR Protocols Jun 2021As a key industrial nitrogenous product and a critical environmental pollutant, ammonia broadly affects our daily lives. Rapid and sensitive detection of ammonia is...
As a key industrial nitrogenous product and a critical environmental pollutant, ammonia broadly affects our daily lives. Rapid and sensitive detection of ammonia is essential to both environmental monitoring and process control for industrial manufacturing. Here, we present a protocol for rapid detection of low amounts of ammonia in the aqueous phase, via surface-enhanced Raman spectroscopy. We believe the mechanism and speed of the approach demonstrate its potential toward applications in electrochemical catalysis and ammonia detection. For complete details on the use and execution of this protocol, please refer to Liu et al. (2020).
Topics: Ammonia; Catalysis; Electrochemical Techniques; Limit of Detection; Spectrum Analysis, Raman; Water
PubMed: 34159324
DOI: 10.1016/j.xpro.2021.100599 -
Microbiology Spectrum Apr 2022This study details a unique process of autothermal thermophilic aerobic digestion (ATAD) of human excreta useful in producing nitrogen-rich and pathogen-free organic...
This study details a unique process of autothermal thermophilic aerobic digestion (ATAD) of human excreta useful in producing nitrogen-rich and pathogen-free organic fertilizer. The process was divided into initial, middle, and final phases, based on changes in temperature, dissolved oxygen (DO), and bacterial community structure. The aim of this study was to determine bacterial factors that would affect liquid fertilizer production in the process, using shotgun metagenomic analysis of each phase. Although the abundances of all 28 gene categories include 4 categories in SEED subsystems level 1 were similar to those in another type of wastewater treatment system, the abundances of 4 gene categories changed remarkably. Among them, a decrease in the abundance of the phage-related gene category and the presence of antibacterial substances in secondary metabolism may explain the change in bacterial community structure from the material to the initial phase. Increases in the abundances of two gene categories, phage-related and secondary metabolism, coincided with a decrease in alpha diversity from the material to the initial phase. A potential increase in the abundance of genes in the category of sporulation from the middle to the final phase was correlated with deterioration of growth conditions and stabilization processes. In addition, prompt consumption of short-chain fatty acids in the initial phase and unusually stable ammonia accumulation throughout the process could be explained by the presence/absence of related metabolic genes. In conclusion, the relationships between bacterial function and unique characteristics of ATAD were revealed; our findings support the enhancement of liquid fertilizer production from wastewater. Metagenome analysis was performed to determine the microbial dynamics of the unique autothermal thermophilic aerobic digestion process of human excreta, which includes initial, middle, and final phases. In this study, we revealed the details of functional genes related to physicochemical and bacterial characteristics in the ATAD process. Four gene categories showed increases and decreases during the digestion process. In addition, the unusual stable accumulation of ammonia and prompt consumption of short-chain fatty acids were explained by the absence or presence of related metabolic genes. In addition to revealing the relationships between bacteria and physicochemical properties, the results of this research may support improving wastewater management systems worldwide by using the ATAD process in liquid fertilizer production systems.
Topics: Ammonia; Bacteria; Biodegradation, Environmental; Bioreactors; Digestion; Fertilizers; Humans; Metagenome; Sewage; Waste Disposal, Fluid; Wastewater
PubMed: 35348372
DOI: 10.1128/spectrum.00561-22 -
Journal of Hazardous Materials Mar 2023Anthropogenic acidification of water is an on-going environmental disaster for freshwater fishes. Fishes rely on ammonia excretion to eliminate the excess acid and...
Anthropogenic acidification of water is an on-going environmental disaster for freshwater fishes. Fishes rely on ammonia excretion to eliminate the excess acid and mitigate the harmful effects; however, it remains largely unknown how ammoniagenesis occurs and is coordinated with ammonia excretion upon acidic stress. Medaka (Oryzias latipes) was used to examine the effects of acidic stress on ammonia production and excretion. We reveal an undiscovered ammonia-producing cell type that is rich in glutaminase (GLS) and located adjacent to the ammonia-excreting ionocytes, Na/H exchanger (NHE) cells, in the gills. The gills, comparing with other ammoniagenetic organs, is the quickest to respond to the acidic stress by triggering GLS-dependent ammonia production. The unique division of labor between GLS and NHE cells in the gills allows medaka to simultaneously upregulate GLS activity and ammonia excretion shortly after exposure to acidic environments. Pharmacological experiment with a GLS inhibitor abolished the activated ammonia excretion, further suggesting the essential role of the unique feature in the responses to acidic stress. Our study shades light on a novel physiological mechanism to timely and efficiently mitigate adverse effects of acidification, providing a new way to assess the impact of on-going environmental acidification on fish.
Topics: Animals; Oryzias; Ammonia; Sodium-Hydrogen Exchangers; Fresh Water; Gills
PubMed: 36502720
DOI: 10.1016/j.jhazmat.2022.130539 -
Water Research Oct 2022A shift from the acetoclastic to the hydrogenotrophic pathway in methanogenesis under ammonia inhibition is a common observation in anaerobic digestion. However, there...
A shift from the acetoclastic to the hydrogenotrophic pathway in methanogenesis under ammonia inhibition is a common observation in anaerobic digestion. However, there are still considerable knowledge gaps concerning the differential ammonia tolerance of acetoclastic and hydrogenotrophic methanogens (AMs and HMs), their responses to different ammonia species (NH, NH), and their recoverability after ammonia inhibition. With the successful enrichment of mesophilic AMs and HMs cultures, this study aimed at addressing the above knowledge gaps through batch inhibition/recovery tests and kinetic modeling under varying total ammonia (TAN, 0.2-10 g N/L) and pH (7.0-8.5) conditions. The results showed that the tolerance level of HMs to free ammonia (FAN, IC=1345 mg N/L) and NH (IC=6050 mg N/L) was nearly 11 times and 3 times those of AMs (NH, IC=123 mg N/L; NH, IC=2133 mg N/L), respectively. Consistent with general belief, the AMs were more impacted by FAN. However, the HMs were more adversely affected by NH when the pH was ≤8.0. A low TAN (1.0-4.0 g N/L) could cause irreversible inhibition of the AMs due to significant cell death, whereas the activity of HMs could be fully or even over recovered from severe ammonia stress (FAN≤ 0.9 g N/L or TAN≤10 g N/L; pH ≤8.0). The different tolerance responses of AMs and HMs might be associated with the cell morphology, multiple energy-converting systems, and Gibbs free energy from substrate-level phosphorylation.
Topics: Ammonia; Anaerobiosis; Bioreactors; Euryarchaeota; Methane
PubMed: 36099760
DOI: 10.1016/j.watres.2022.119029 -
Frontiers in Bioscience (Elite Edition) Dec 2023Conventional ammonia production methods, notably the energy-intensive Haber-Bosch process, are costly and contribute substantially to about 2% of the world's CO2...
BACKGROUND
Conventional ammonia production methods, notably the energy-intensive Haber-Bosch process, are costly and contribute substantially to about 2% of the world's CO2 emissions. This study focuses on the biological approach to convert protein to ammonia via hyper-ammonia-producing bacteria (HAB) fermentation.
METHODS
A consortium of ruminal microbes was employed in this work to ferment soybean meal protein under varying processing conditions. The parameters investigated included pH (7-11), inoculum concentrations (1-10%), substrate concentrations (5-20%), and fermentation time (0-168 h).
RESULTS
Optimal conditions for microbial growth and biological ammonia production were observed at pH 7, fermentation duration of 72 h, inoculum concentration of 10%, and substrate concentration of 10%. ~8000 mg/L biological ammonia was produced following HAB fermentation.
CONCLUSIONS
By leveraging the capabilities of rumen HAB, this study contributes to the ongoing efforts to develop environmentally friendly processes for ammonia production that will mitigate both economic and environmental concerns associated with traditional methods.
Topics: Animals; Fermentation; Soybean Proteins; Ammonia; Anaerobiosis; Rumen; Animal Feed
PubMed: 38163937
DOI: 10.31083/j.fbe1504027 -
Applied and Environmental Microbiology Feb 2023Complete ammonia oxidizers (comammox) are a group of ubiquitous chemolithoautotrophic bacteria capable of deriving energy from the oxidation of ammonia to nitrate via...
Complete ammonia oxidizers (comammox) are a group of ubiquitous chemolithoautotrophic bacteria capable of deriving energy from the oxidation of ammonia to nitrate via nitrite. Here, we present a study characterizing the comammox strain sp. BO4 using a combination of cultivation-dependent and molecular methods. The enrichment culture BO4 was obtained from the sediment of Lake Burr Oak, a mesotrophic lake in eastern Ohio. The metagenome of the enrichment culture was sequenced, and a metagenome-assembled genome (MAG) was constructed for sp. BO4. The closest characterized relative of sp. BO4 was " Nitrospira kreftii." All genes for ammonia and nitrite oxidation, reductive tricarboxylic acid (TCA) cycle, and other pathways of the central metabolism were detected. sp. BO4 used ammonia and oxidized it to nitrate with nitrite as the intermediate. The culture grew on initial ammonium concentrations between 0.01 and 3 mM with the highest rates observed at the lowest ammonium concentrations. Blue light completely inhibited the growth of sp. BO4, while white light reduced the growth and red light had no effect on the growth. sp. BO4 did not grow on nitrite as its sole substrate. When supplied with ammonium and nitrite, the culture utilized nitrite after most of the ammonium was consumed. In summary, the genomic information of sp. BO4 coupled with the growth experiments shows that sp. BO4 is a freshwater comammox species. Future research will focus on further characterization of the niches of comammox in freshwater environments. Nitrification is a key process in the global nitrogen cycle. Complete ammonia oxidizers (comammox) were discovered recently, and only three enrichment cultures and one pure culture have been characterized with respect to activity and growth under different conditions. The cultivated comammox strains were obtained from engineered systems such as a recirculating aquaculture system and hot water pipes. Here, we present the first study characterizing a comammox strain obtained from a mesotrophic freshwater lake. In freshwater environments, comammox coexist with ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). Our results will help elucidate physiological characteristics of comammox and the distribution and niche differentiation of different ammonia oxidizers in freshwater environments.
Topics: Ammonia; Nitrites; Nitrates; Bacteria; Archaea; Nitrification; Oxidation-Reduction; Genomics; Fresh Water; Ammonium Compounds; Phylogeny
PubMed: 36719237
DOI: 10.1128/aem.01965-22 -
Water Research Nov 2022The toxic effect of unionized ammonia (NH) on aquatic organisms is receiving increasing attention due to the excessive nitrogen discharge to various surface waters....
The toxic effect of unionized ammonia (NH) on aquatic organisms is receiving increasing attention due to the excessive nitrogen discharge to various surface waters. Researches have suggested the scale-dependence of NH toxicity, being lower in field than under lab conditions. Such scale-dependence of toxicity is a big challenge to water quality criteria setting as the results solely from lab tests might not apply to natural ecosystems. Therefore, it is necessary to explore the underlying mechanism to understand the difference of toxicity across various spatial scales. In this study, we used the widely distributed gastropod Bellamya aeruginosa as the test animal and performed two 192-h microcosm experiments. Each experiment included a control and an ammonia addition treatment: N0(LC) & N+(LC), N0(LC) & N+(LC) (96-h LC = 0.8 mg NHN/L, 96-h LC = 18.1 mg NHN/L). Besides water-only, three potential key components (food, sediment, and submersed macrophytes) were included in the various treatments to mimic different complexity levels of aquatic ecosystems (Water, Water + Food, Water + Sediment, Water + Sediment + Macrophytes). The results showed that: 1) food directly improved the survival and growth of gastropods under expected lethal concentration of ammonia (96-h concentration of NHN = LC of the 96-h acute test); 2) sediment and macrophyte quickly decreased the ammonia concentration, mainly by sediment adsorption and macrophyte uptake, to alleviate the ammonia stress to gastropods and permitted them to survive and grow under expected lethal concentration of ammonia (96-h concentration of NHN = LC∼LC of the 96-h acute test); 3) sediment and macrophyte also provided additional food for gastropods; 4) under extremely high ammonia stress (i.e., 96-h LC, food was left uneaten and macrophyte died, and gastropods could, therefore, not be released from ammonia stress. Our results demonstrate that under moderate ammonia stress, the introduction of extra ecosystem elements (food, sediment, and macrophytes) significantly improved the survival and growth of gastropods, mainly by enhancing their tolerance and by quickly decreasing the NH concentration and thus toxicity. However, these introduced elements had little effect at very high concentration of ammonia (i.e., 96-h LC). Our findings add to the understanding of the reasons behind the previous observed scale-dependent toxicity of NH on aquatic organisms and contribute to better decisions on the role of NH in relation to water quality management.
Topics: Animals; Ecosystem; Ammonia; Aquatic Organisms; Nitrogen; Water Pollutants, Chemical
PubMed: 36323203
DOI: 10.1016/j.watres.2022.119266 -
Ecotoxicology and Environmental Safety Oct 2022Ammonia pollutants were usually found in aquatic environments is due to urban sewage, industrial wastewater discharge, and agricultural runoff and concentrations as high...
Ammonia pollutants were usually found in aquatic environments is due to urban sewage, industrial wastewater discharge, and agricultural runoff and concentrations as high as 180 mg/L (NH) have been reported in rivers. High ammonia levels are known to impair multiple tissue and cell functions and cause fish death. Although ammonia is a potent neurotoxin, how sublethal concentrations of ammonia influence the central nervous system (CNS) and the complex behaviors of fish is still unclear. In the present study, we demonstrated that acute sublethal ammonia exposure can change social behavior of adult zebrafish. The exposure to 90 mg /L of (NH) for 4 h induced a strong fear response and lower shoaling cohesion; exposure to 180 mg /L of (NH) for 4 h reduced the aggressiveness, and social recognition, while the anxiety, social preference, learning, and short-term memory were not affected. Messenger RNA expressions of glutaminase and glutamate dehydrogenase in the brain were induced, suggesting that ammonia exposure altered glutamate neurotransmitters in the CNS. Our findings in zebrafish provided delicate information of ammonia neurotoxicity in complex higher-order social behaviors, which has not been revealed previously. In conclusion, sublethal and acute ammonia exposure can change specific behaviors of fish, which might lead to reductions in individual and population fitness levels.
Topics: Ammonia; Animals; Anxiety; Cognition; Glutamate Dehydrogenase; Glutamates; Glutaminase; Neurotoxins; RNA, Messenger; Sewage; Social Behavior; Wastewater; Water Pollutants, Chemical; Zebrafish
PubMed: 36108432
DOI: 10.1016/j.ecoenv.2022.114058