nitrogen cycle

(noun)

The natural circulation of nitrogen, in which atmospheric nitrogen is converted to nitrogen oxides by lightning and deposited in the soil by rain where it is assimilated by plants and either eaten by animals (and returned as feces) or decomposed back to elemental nitrogen by bacteria.

Examples of nitrogen cycle in the following topics:

  • The Nitrogen Cycle

    • The nitrogen cycle is the process by which nitrogen is converted from organic to inorganic forms; many steps are performed by microbes.
    • The nitrogen cycle describes the conversion of nitrogen between different chemical forms.
    • Nitrogen is essential for the formation of amino acids and nucleotides.
    • It can either be cycled back into a plant usable form through nitrification or returned to the atmosphere through de-nitrification.
    • Describe the nitrogen cycle and how it is affected by human activity

  • Nitrospirae and Deferribacter

    • Nitrospirae is a phylum of bacteria; some nitrospirae species perform important functions in the nitrogen cycle.
    • Some nitrospirae species perform important functions in the Nitrogen Cycle :
    • The Nitrogen Cycle describes the changes in nitrogenous compounds in the environment.
    • Because many of them are toxic, it is important to know something about this cycle.
    • Luckily, these compounds are converted to less and less toxic forms through this Nitrogen Cycle.

  • Anammox

    • Anammox, an abbreviation for ANaerobic AMMonium OXidation, is a globally significant microbial process of the nitrogen cycle.
    • Anammox, an abbreviation for ANaerobic AMMonium OXidation , is a globally significant microbial process of the nitrogen cycle.
    • Because of this property, these organisms could be used industrially to remove nitrogen in wastewater treatment processes.

  • Nitrification

    • Nitrobacter plays an important role in the nitrogen cycle by oxidizing nitrite into nitrate in soil.
    • Nitrification is an important step in the nitrogen cycle in soil.
    • Nitrification is a process of nitrogen compound oxidation (effectively, loss of electrons from the nitrogen atom to the oxygen atoms):
    • Schematic representation of the flow of nitrogen through the environment.
    • The importance of bacteria in the cycle is immediately recognized as being a key element in the cycle, providing different forms of nitrogen compounds assimilable by higher organisms.

  • Nitrogenase and Nitrogen Fixation

    • Nitrogen fixation also refers to other biological conversions of nitrogen, such as its conversion to nitrogen dioxide.
    • Nitrogen fixation is a process by which nitrogen (N2) in the atmosphere is converted into ammonia (NH3).
    • Atmospheric nitrogen or elemental nitrogen (N2) is relatively inert: it does not easily react with other chemicals to form new compounds.
    • Microorganisms that fix nitrogen are bacteria called diazotrophs.
    • Biological nitrogen fixation (BNF) occurs when atmospheric nitrogen is converted to ammonia by an enzyme called nitrogenase.

  • Sources and Sinks of Essential Elements

    • Most important substances on Earth, such as oxygen, nitrogen, and water undergo turnover or cycling through both the biotic (living) and abiotic (geological, atmospheric, and hydrologic) compartments of the Earth.
    • Ecosystems hinge on biogeochemical cycles.
    • The nitrogen cycle, the phosphorous cycle, the sulfur cycle, and the carbon cycle all involve assimilation of these nutrients into living things.
    • The atmosphere is considered a reservoir for nitrogen.
    • This flow from abiotic to biotic compartments of the Earth is typical of biogeochemical cycles.

  • Role of Microbes in Biogeochemical Cycling

    • Nutrients move through the ecosystem in biogeochemical cycles.
    • A biogeochemical cycle is a pathway by which a chemical element (such as carbon or nitrogen) circulates through the biotic (living) and the abiotic (non-living) factors of an ecosystem.
    • A good example of a molecule that is cycled within an ecosystem is water, which is always recycled through the water cycle.
    • The key collective metabolic processes of microbes (including nitrogen fixation, carbon fixation, methane metabolism, and sulfur metabolism) effectively control global biogeochemical cycling.
    • Consequently, chemical processing of nitrogen (or nitrogen fixation) is necessary to convert gaseous nitrogen into forms that living organisms can use.

  • Betaproteobacteria

    • They play an important role in the nitrogen cycle by increasing the availability of nitrogen to plants while limiting carbon dioxide fixation.
    • Betaproteobacteria play a role in nitrogen fixation in various types of plants, oxidizing ammonium to produce nitrite- an important chemical for plant function.

  • Ocean Floor

    • These microbes play a vital role in biogeochemical cycles.
    • The nitrogen cycle, the phosphorus cycle and the carbon cycle all depend on microorganisms in one way or another.
    • For example, nitrogen which makes up 78% of the planet's atmosphere is "indigestible" for most organisms, and the flow of nitrogen into the biosphere depends on a microbial process called fixation.

  • The Phosphorus Cycle

    • The phosphorous cycle differs from other nutrient cycles, because it never passes through a gaseous phase like the nitrogen or carbon cycles .
    • The phosphorous cycle is affected by human activities.