"The iron cycle (Fe) is the biogeochemical cycle of iron through the atmosphere, hydrosphere, biosphere, and lithosphere."
The cycle of handling of iron in various geological forms.
Biogeochemistry: The study of the chemical, physical, geological, and biological processes and reactions that control the composition and dynamics of the Earth's systems.
Iron oxidation: The process by which iron is converted from a soluble, oxidized form to a particulate, reduced form, which can then be utilized by microorganisms.
Iron reduction: The process by which iron is transformed from a solid, insoluble form to a soluble, reduced form, which can then be utilized by microorganisms.
Iron cycling: The overall process by which iron is oxidized, reduced, and transported through the environment.
Microbial ecology: The study of the relationships between microorganisms and the environment in which they live.
Metagenomics: The study of microbial communities and their genetic content.
Geochemistry: The study of the chemical composition of rocks, minerals, soils, and other Earth materials.
Sedimentology: The study of sedimentary rocks and the processes that form them.
Paleoclimate: The study of past climates and the factors that influence climate change.
Deep-sea vents: Hydrothermal vents on the ocean floor that provide energy and nutrients for unique ecosystems.
Iron isotopes: The different isotopes of iron can provide information about the sources and cycling of iron in the environment.
Biomineralization: The process by which living organisms produce minerals, such as shells or bones.
Phosphorus cycling: The overall process by which phosphorus is cycled through the environment.
Bioremediation: The use of microorganisms to clean up environmental pollutants.
Ecosystem functioning: The study of how ecosystems work and the roles that different organisms play in maintaining them.
Phototrophic Iron Oxidation: This type of iron cycle involves the oxidation of iron by bacteria that use sunlight as an energy source. They use this energy to convert ferrous iron (Fe2+) to ferric iron (Fe3+).
Chemoautotrophic Iron Oxidation: In this type of iron cycle, bacteria oxidize ferrous iron (Fe2+) to ferric iron (Fe3+) as a source of energy. They do not require sunlight and instead use chemical energy sources from their surrounding environment.
Iron Reduction: This type of iron cycle involves the reduction of ferric iron (Fe3+) to ferrous iron (Fe2+), which is carried out by bacterial species, such as Geobacter spp.
Anaerobic Ferrous Oxidation: In this type of iron cycle, bacteria use ferrous iron (Fe2+) as a source of energy, producing ferric iron (Fe3+), and come in contact with oxygen.
Microbial Iron Sulfide Formation: This type of iron cycle involves the interaction of iron and sulfur bacteria, leading to the formation of iron sulfides.
Dissimilatory Ferric Iron Reduction: This type of iron cycle involves the reduction of ferric iron (Fe3+) to ferrous iron (Fe2+) by bacteria as a source of energy. The process is carried out in anaerobic environments.
Iron Methanogenesis: In this type of iron cycle, iron-reducing microorganisms catalyze the reduction of native ferric iron (Fe3+) in the sediments or soils, ultimately leading to the production of methane.
Iron-oxidizing Archaea: This type of iron cycle involves the oxidation of iron and generates energy in the Archaea domain.
"While Fe is highly abundant in the Earth's crust, it is less common in oxygenated surface waters."
"Iron is a key micronutrient in primary productivity, and a limiting nutrient in the Southern ocean, eastern equatorial Pacific, and the subarctic Pacific referred to as High-Nutrient, Low-Chlorophyll (HNLC) regions of the ocean."
"Iron exists in a range of oxidation states from -2 to +7; however, on Earth, it is predominantly in its +2 or +3 redox state."
"The cycling of iron between its +2 and +3 oxidation states is referred to as the iron cycle."
"The abiotic processes include the rusting of iron-bearing metals, where Fe2+ is abiotically oxidized to Fe3+ in the presence of oxygen, and the reduction of Fe3+ to Fe2+ by iron-sulfide minerals."
"The biological cycling of Fe2+ is done by iron-oxidizing and reducing microbes."
"Iron is an essential micronutrient for almost every life form."
"It is a key component of hemoglobin, important to nitrogen fixation as part of the Nitrogenase enzyme family, and as part of the iron-sulfur core of ferredoxin it facilitates electron transport in chloroplasts, eukaryotic mitochondria, and bacteria."
"Due to the high reactivity of Fe2+ with oxygen and low solubility of Fe3+, iron is a limiting nutrient in most regions of the world."
"The iron cycle involves the atmosphere, hydrosphere, biosphere, and lithosphere."
"While Fe is less common in oxygenated surface waters, there may be regions where it is more abundant."
"Iron is a key micronutrient in primary productivity, supporting the growth of organisms in various ecosystems."
"The Southern ocean, eastern equatorial Pacific, and the subarctic Pacific are known as High-Nutrient, Low-Chlorophyll (HNLC) regions of the ocean where iron is a limiting nutrient."
"On Earth, iron is predominantly found in its +2 or +3 redox state."
"The abiotic processes include the rusting of iron-bearing metals and the reduction of Fe3+ to Fe2+ by iron-sulfide minerals."
"Iron oxidizing and reducing microbes play a role in the biological cycling of Fe2+."
"Iron is a key component of hemoglobin, nitrogen fixation enzymes, and electron transport systems in various cells."
"Iron is a limiting nutrient in most regions of the world due to its high reactivity with oxygen and low solubility."
"Iron, as part of the iron-sulfur core of ferredoxin, facilitates electron transport in chloroplasts, eukaryotic mitochondria, and bacteria."