Hydrogenotrophs are

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

s that are able to

metabolize Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the ...

molecular

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

as a source of

energy Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and l ...

. An example of hydrogenotrophy is performed by

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

-reducing organismsStams, J.M., and Plugge, C.M. (2010) The microbiology of methanogenesis. ''In'' Reay, D., Smith, P., and Van Amstel, A., eds. ''Methane and Climate Change'', 14-26. which use CO₂ and H₂ to produce

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...

(CH₄) by the following reaction: *CO₂ + 4H₂ → CH₄ + 2H₂O Other hydrogenotrophic metabolic pathways include

acetogenesis Acetogenesis is a process through which acetyl-CoA or acetic acid is produced by anaerobic bacteria through the Redox, reduction of Carbon dioxide, via the Wood–Ljungdahl pathway. Other microbial processes that produce acetic acid (like certain ...

sulfate reduction The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many a ...

, and other hydrogen oxidizing bacteria. Those that metabolize methane are called

methanogenic Methanogenesis or biomethanation is the formation of methane coupled to energy conservation by microbes known as methanogens. It is the fourth and final stage of anaerobic digestion. Organisms capable of producing methane for energy conservation h ...

. Hydrogenotrophs belong to a group of organisms known as

methanogens Methanogens are anaerobic archaea that produce methane as a byproduct of their energy metabolism, i.e., catabolism. Methane production, or methanogenesis, is the only biochemical pathway for ATP generation in methanogens. All known methanogens b ...

, organisms that carry out anaerobic processes that are responsible for the production of methane through carbon dioxide reduction. Methanogens also include a group of organisms called methylotrophs, organisms that can use single-carbon molecules or molecules with no carbon-carbon bonds.

Background Information

Hydrogenotrophic bacteria were first experimented with by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

in the 1960s in order to find a replenishable food source. Hydrogenotrophic bacteria have been found to have a high protein and carbohydrate content and have been a guiding principle in developing sustainable agricultural methods. Experimentation has revealed that hydrogenotrophic bacteria can convert carbon dioxide into food more rapidly than plants, making them an efficient and sustainable alternative to implement into plant-based high-protein diets and as a substitute in products that use plant extracts and oils. In September 2022, finnish biotech startup Solar Foods received its first food regulatory approval from the

Singapore Food Agency The Singapore Food Agency (SFA) is a statutory board under the Ministry of Sustainability and the Environment that oversees food safety and security in Singapore. History The agency was first announced on 26 July 2018 as a consolidation of all ...

(SFA) for a protein supplement ( Solein) derived from hydrogenotrophic microorganisms, and has since started production in a commercial-scale facility. Hydrogenotrophs are commonly found in the human gut, along with other

fermentative Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduced ...

bacteria which live in symbiosis with one another. They are also found in soils and in sediments of freshwater and marine ecosystems around the world.

References

Environmental microbiology Prokaryotes {{microbiology-stub

Background Information

See also

References