Hydrogenotrophs are

organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...

s that are able to

metabolize Metabolism (, from el, μεταβολή ''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 cell ...

molecular

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...

as a source of

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...

. An example of hydrogenotrophy is performed by

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

-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 relative abundance of methane on Eart ...

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

acetogenesis Acetogenesis is a process through which acetate is produced either by the reduction of CO2 or by the reduction of organic acids, rather than by the oxidative breakdown of carbohydrates or ethanol, as with acetic acid bacteria. The different bacte ...

, sulfate reduction, and other

hydrogen oxidizing bacteria Hydrogen-oxidizing bacteria are a group of facultative autotrophs that can use hydrogen as an electron donor. They can be divided into aerobes and anaerobes. The former use hydrogen as an electron donor and oxygen as an acceptor while the latter u ...

. Those that metabolize methane are called

methanogenic Methanogenesis or biomethanation is the formation of methane coupled to energy conservation by microbes known as methanogens. Organisms capable of producing methane for energy conservation have been identified only from the Domain (biology), domai ...

. Hydrogenotrophs belong to a group of organisms known as

methanogens Methanogens are microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain Archaea. All known methanogens are members of the archaeal phylum Euryarchaeota. Methanogens are comm ...

, 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 agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

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. Hydrogenotrophs are commonly found in the human gut, along with other fermentative 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