|
Nitrification
''Nitrification'' is the biological oxidation of ammonia to nitrite followed by the oxidation of the nitrite to nitrate occurring through separate organisms or direct ammonia oxidation to nitrate in comammox bacteria. The transformation of ammonia to nitrite is usually the rate limiting step of nitrification. Nitrification is an important step in the nitrogen cycle in soil. Nitrification is an aerobic process performed by small groups of autotrophic bacteria and archaea. Microbiology Ammonia oxidation The oxidation of ammonia into nitrite (also known as nitritation) is performed by two groups of organisms, ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). AOB AOB can be found among the Betaproteobacteria and Gammaproteobacteria. Since discovery of AOA in 2005, two isolates have been cultivated: ''Nitrosopumilus maritimus'' and ''Nitrososphaera viennensis''. In soils the most studied AOB belong to the genera ''Nitrosomonas'' and '' Nitrococcus''. AOA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Cycle
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems. The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Cycle
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems. The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrosomonas
''Nitrosomonas'' is a genus of Gram-negative bacteria, belonging to the Betaproteobacteria. It is one of the five genera of ammonia-oxidizing bacteria and, as an obligate chemolithoautotroph, uses ammonia (NH3) as an energy source and carbon dioxide (CO2) as a carbon source in presence of oxygen. ''Nitrosomonas'' are important in the global biogeochemical nitrogen cycle, since they increase the bioavailability of nitrogen to plants and in the denitrification, which is important for the release of nitrous oxide, a powerful greenhouse gas. This microbe is photophobic, and usually generate a biofilm matrix, or form clumps with other microbes, to avoid light. ''Nitrosomonas'' can be divided into six lineages: the first one includes the species '' Nitrosomonas europea'', ''Nitrosomonas eutropha'', ''Nitrosomonas halophila'', and ''Nitrosomonas mobilis.'' The second lineage presents the species ''Nitrosomonas communis'', ''N. sp. I'' and ''N. sp. II,'' meanwhile the third lineage include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrifying Bacteria
Nitrifying bacteria are chemolithotrophic organisms that include species of genera such as ''Nitrosomonas'', ''Nitrosococcus'', ''Nitrobacter'', '' Nitrospina'', ''Nitrospira'' and '' Nitrococcus''. These bacteria get their energy from the oxidation of inorganic nitrogen compounds. Types include ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). Many species of nitrifying bacteria have complex internal membrane systems that are the location for key enzymes in nitrification: ammonia monooxygenase (which oxidizes ammonia to hydroxylamine), hydroxylamine oxidoreductase (which oxidizes hydroxylamine to nitric oxide - which is further oxidized to nitrite by a currently unidentified enzyme), and nitrite oxidoreductase (which oxidizes nitrite to nitrate). Ecology Nitrifying bacteria are present in distinct taxonomical groups and are found in highest numbers where considerable amounts of ammonia are present (such as areas with extensive protein decomposition, and sewage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comammox
Comammox (COMplete AMMonia OXidation) is the name attributed to an organism that can convert ammonia into nitrite and then into nitrate through the process of nitrification. Nitrification has traditionally thought to be a two-step process, where ammonia-oxidizing bacteria and archaea oxidize ammonia to nitrite and then nitrite-oxidizing bacteria convert to nitrate. Complete conversion of ammonia into nitrate by a single microorganism was first predicted in 2006. In 2015 the presence of microorganisms that could carry out both conversion processes was discovered within the genus ''Nitrospira,'' and the nitrogen cycle was updated. Within the genus ''Nitrospira,'' the major ecosystems comammox are primarily found in natural aquifers and engineered ecosystems. Complete nitrification step yield more energy (∆G°′ = −349 kJ mol−1 NH3) than either single oxidation alone (∆G°′ = −275 kJ mol−1 NH3 for ammonia oxidation to nitrite and ∆G°′ = −74 kJ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betaproteobacteria
Betaproteobacteria are a class of Gram-negative bacteria, and one of the eight classes of the phylum Pseudomonadota (synonym Proteobacteria). The ''Betaproteobacteria'' are a class comprising over 75 genera and 400 species of bacteria. Together, the ''Betaproteobacteria'' represent a broad variety of metabolic strategies and occupy diverse environments from obligate pathogens living within host organisms to oligotrophic groundwater ecosystems. Whilst most members of the ''Betaproteobacteria'' are heterotrophic, deriving both their carbon and electrons from organocarbon sources, some are photoheterotrophic, deriving energy from light and carbon from organocarbon sources. Other genera are autotrophic, deriving their carbon from bicarbonate or carbon dioxide and their electrons from reduced inorganic ions such as nitrite, ammonium, thiosulfate or sulfide — many of these chemolithoautotrophic. ''Betaproteobacteria'' are economically important, with roles in maintaining soil p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Warington (agricultural Chemist, Born 1838)
Robert Warington, Jr. (22 August 1838, Spitalfields, London – 20 March 1907, Harpenden) was an English agricultural chemist, known for his research and publications on the chemistry of phosphates and nitrates in agricultural soils. Biography Robert Warington Jr. was the eldest son and second child of the chemist Robert Warington, FRS. After studying chemistry in his father's laboratory and attending lectures by Faraday, Brande, and Hofmann, Robert Warington Jr. became in 1859 an unpaid assistant to Sir John Bennet Lawes at Rothamsted Experimental Station at Harpenden. Warington was from 1862 to 1867 an assistant to the Professor of Chemistry at the Royal Agricultural College at Cirencester. He was from 1876 to 1891 an investigator at Rothamsted Experimental Stations, where he published many articles on soil nitrification. R. Warington here made the first observation that nitrification is a two-step process in 1879. In 1891 Warington was appointed by the committee for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achille Müntz
Charles Achille Müntz (10 August 1846 – 20 February 1917) was a French agricultural chemist. Biography He was born at Soultz-sous-Forêts, Alsace, studied under Jean-Baptiste Boussingault in Paris, and, after acting as his assistant for ten years, succeeded him as director of the chemical laboratories in the Institut National Agronomique (1887–1914). From 1907 to 1914 he was also director of the research station for plant chemistry at Meudon (Collège de France).MÜNTZ Charles Achille Sociétés savantes de France He was a member of the (1896–1917) and the |
Nitrospinota
Nitrospinota is a bacterial phylum. Despite only few described species, members of this phylum are major nitrite-oxidizing bacteria in surface waters in oceans. By oxidation of nitrite to nitrate they are important in the process of nitrification in marine environments. Although genus Nitrospina is aerobic bacterium, it was shown to oxidize nitrite also in oxygen minimum zone of the ocean. Depletion of oxygen in such zones leads to preference of anaerobic processes such as denitrification and nitrogen loss through anammox. Nitrospina thus outweight nitrogen loss by nitrification also in these oxygen depleted zones. Among the cultivated isolates within the genus ''Nitrospina'' are '' Nitrospina gracilis'' and '' Nitrospina watsonii''. Further genomes were resolved by culture-independent metagenome binning. The two ''Nitrospina'' species are, however, distantly related to environmentally abundant uncultured Nitrospinota. The two other strains were cultivated in 2020 each in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid phase of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three-state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem. Most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrososphaerota
The Nitrososphaerota (syn. Thaumarchaeota) are a phylum of the Archaea proposed in 2008 after the genome of ''Cenarchaeum symbiosum'' was sequenced and found to differ significantly from other members of the hyperthermophilic phylum Thermoproteota (formerly Crenarchaeota). Three described species in addition to ''C. symbiosum'' are ''Nitrosopumilus maritimus'', ''Nitrososphaera viennensis'', and ''Nitrososphaera gargensis''. The phylum was proposed in 2008 based on phylogenetic data, such as the sequences of these organisms' ribosomal RNA genes, and the presence of a form of type I topoisomerase that was previously thought to be unique to the eukaryotes. This assignment was confirmed by further analysis published in 2010 that examined the genomes of the ammonia-oxidizing archaea ''Nitrosopumilus maritimus'' and ''Nitrososphaera gargensis'', concluding that these species form a distinct lineage that includes ''Cenarchaeum symbiosum''. The lipid crenarchaeol has been found only i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrospira Inopinata
''Nitrospira inopinata'' is a bacterium from the phylum Nitrospirota. This phylum contains nitrite-oxidizing bacteria playing role in nitrification. However ''N. inopinata'' was shown to perform complete ammonia oxidation to nitrate thus being the first comammox bacterium to be discovered. ''N. inopinata'' was cultivated in enrichment culture. Initial inoculum was obtained in 2011 from microbial biofilm growing on metal surface of the pipe covered by hot water (56 °C, pH 7.5), which was raised from 1 200m deep oil exploration well. The well was located in Aushiger, North Caucasus, Russia. The growth in pure culture was achieved in 2017. Genome of ''N. inopinata'' was released in 2015 represented by 3.3 Mbp, with 3 116 genes and 59.2% GC content. NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
