Radiosynthesis is the theorized capture andmetabolism, by living organisms, of energy fromionizing radiation, analogously tophotosynthesis. Metabolism of ionizing radiation was theorized as early as 1956 by the Russian microbiologistS. I. Kuznetsov.[1]
Beginning in the 1990s, researchers at theChernobyl Nuclear Power Plant uncovered some 200 species of apparentlyradiotrophic fungi containing the pigmentmelanin on the walls of the reactor room and in the surrounding soil.[2][3] Such "melanized" fungi have also been discovered in nutrient-poor, high-altitude areas which are exposed to high levels ofultraviolet radiation.[4]
Following the Ukrainian results, an American team at theAlbert Einstein College of Medicine ofYeshiva University 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 thatCryptococcus neoformans fungi grew three times faster than normal.[5][4] Microbiologist Ekaterina Dadachova suggested such fungi could serve as a food supply and source ofradiation protection forinterplanetary astronauts, who would be exposed tocosmic rays.[4]
In 2014, the American research group was awarded a patent for a method of enhancing the growth ofmicroorganisms through increasing melanin content. The inventors of this process claimed theirfungi were employing radiosynthesis, and hypothesized that radiosynthesis may have played a role in early life on Earth, by allowing melanized fungi to act asautotrophs.[6]
From October 2018 through March 2019,NASA conducted an experiment aboard theInternational Space Station 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-altitudebiofuel or a nutrition source.[7]