Radiosynthesis is the theorized capture and

metabolism 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 co ...

, by living organisms, of energy from

ionizing radiation Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, ionize atoms or molecules by detaching ...

, analogously to

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

. Metabolism of ionizing radiation was theorized as early as 1956 by the Russian microbiologist S. I. Kuznetsov. Beginning in the 1990s, researchers at the Chernobyl Nuclear Power Plant uncovered some 200 species of apparently radiotrophic fungi containing the pigment

melanin Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are ...

on the walls of the reactor room and in the surrounding soil. Such "melanized" fungi have also been discovered in nutrient-poor, high-altitude areas which are exposed to high levels of

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

radiation. Following the Ukrainian results, an American team at the

Albert Einstein College of Medicine The Albert Einstein College of Medicine is a Private university, private medical school in New York City. Founded in 1953, Einstein is an independent degree-granting institution within the Montefiore Einstein Health System. Einstein hosts Doc ...

Yeshiva University Yeshiva University is a Private university, private Modern Orthodox Judaism, Orthodox Jewish university with four campuses in New York City.

in New York began experimenting with radiation exposure of melanin and melanized fungi. They found that ionizing radiation increased the ability of melanin to support an important metabolic reaction, and that '' Cryptococcus neoformans'' fungi grew three times faster than normal. Microbiologist Ekaterina Dadachova suggested such fungi could serve as a food supply and source of

radiation protection Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Exposu ...

for interplanetary astronauts, who would be exposed to

cosmic ray Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the ...

s. In 2014, the American research group was awarded a patent for a method of enhancing the growth of

microorganisms A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

through increasing melanin content. The inventors of this process claimed their

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

were employing radiosynthesis, and hypothesized that radiosynthesis may have played a role in early life on Earth, by allowing melanized fungi to act as

autotroph An autotroph is an organism that can convert Abiotic component, abiotic sources of energy into energy stored in organic compounds, which can be used by Heterotroph, other organisms. Autotrophs produce complex organic compounds (such as carbohy ...

s. From October 2018 through March 2019,

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 ...

conducted an experiment aboard the

International Space Station The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...

to study radiotrophic fungi as a potential radiation barrier to the harmful radiation in space. Radiotrophic fungi have many possible applications on Earth as well, potentially including a disposal method for nuclear waste or use as high-altitude

biofuel Biofuel is a fuel that is produced over a short time span from Biomass (energy), biomass, rather than by the very slow natural processes involved in the formation of fossil fuels such as oil. Biofuel can be produced from plants or from agricu ...

or a nutrition source.

References

{{reflist Radiobiology Biochemistry Photochemistry Metabolism