Researchers have discovered various types of bacteria and fungi that have the ability to consume radiation. These microorganisms can utilize radioactive chemicals as a source of energy or as nutrients for their metabolic processes. Some examples of such bacteria include Burkholderia fungorum and Geobacter species. Additionally, certain fungi like Cladosporium sphaerospermum, Cryptococcus neoformans, and Wangiella dermatitidis possess melanin, a pigment that can absorb radiation.
Fukushima Daichii (Japan, 2011), Chernobyl (Ukraine, 1986), Three Mile Island (U.S.A, 1978), Windscale (U.K, 1957)….
Chernobyl Exclusion Zone (Photo Credit: Eight Photo/Shutterstock)
These are just a few examples of the most severe nuclear accidents that have occurred worldwide.
Chernobyl is considered the most catastrophic accident so far, as the area surrounding the Chernobyl nuclear power plant is expected to be unfit for human habitation for approximately 20,000 years due to the dangerous radiation released by the explosion.
However, explosions are not the sole source of concern in relation to nuclear power plants.
The issue of disposing of nuclear waste produced by these reactors is also a significant concern. These reactors operate using highly radioactive materials, like uranium, which break down into other radioactive substances, rendering them virtually indestructible. The ionizing radiation emitted by uranium and its derivatives has the ability to change our DNA, and prolonged exposure raises the likelihood of developing cancer.
The Disposal of Nuclear Waste
At present, the radioactive waste that is produced is cooled down and stored in sizable stainless steel containers that are encompassed by concrete. Enormous quantities of nuclear waste are encapsulated in concrete and buried deep beneath the Earth’s surface. Although these methods are currently viable, they are not sustainable due to the increasing global population. Moreover, the burial of radioactive waste also poses the risk of its contents seeping into the surrounding environment and entering the food chain. Is there a more effective and permanent solution to dispose of this radioactive waste?
Radioactive waste is being kept in barrels below ground (Photo Credit: josefkubes/Shutterstock)
The Use of Radiation-Eating Microbes for Nuclear Waste Disposal
Thanks to the assistance of tiny, adaptable organisms, we are able to effectively eliminate nuclear waste. Researchers from the University of Manchester have discovered indications of Geobacter, a specific bacteria species that not only withstands radiation exposure, but also harnesses its energy.
Geobacter species have a distinctive capability to oxidize organic substances and metals, such as iron and radioactive metals. They are even capable of thriving in environments that lack oxygen, such as deep underground areas with high alkalinity, like the regions where nuclear waste is deposited underground.
When groundwater comes into contact with the concrete vaults that contain nuclear waste, their interaction results in an increase in alkalinity.
Certain types of nuclear waste can contain cellulose, which is derived from materials like used filters and work clothing. When exposed to high alkalinity, cellulose breaks down into a substance called isosaccharinic acid (ISA). When ISA comes into contact with uranium, it can react to form a compound that is more soluble. This compound has the potential to leak out and contaminate groundwater.
Geobacter is capable of averting a potentially lethal catastrophe by breaking down ISA and utilizing it as nourishment and power. As a result, uranium reverts back to its initial insoluble, solid state. In this state, uranium cannot contaminate the potable water or the food chain, thus preserving innumerable lives.
In a separate occurrence, the U.S. Department of Energy’s research project discovered a bacterial variant known as Burkholderia fungorum that utilizes uranium. This strain was obtained from the Integrated Field-Scale Subsurface Research Challenge Site (IFRC) located in Rifle, Colorado (USA).
This discovery was significant because, during that time (April, 2015), there had been no known connection between members of the Burkholderiaceae family and uranium reduction.
This is a unique characteristic of bacterial species, where they can exchange genetic material (DNA) if they are in close proximity. The exchanged DNA can lead to resistance to antibiotics or heavy metal toxicity. B. fungorum, specifically, may have acquired some DNA that enables it to reduce uranium.
Scientists believe that this new ability to reduce uranium was acquired by the bacteria from other uranium-breathing bacteria present in the area.
Methods of bacterial gene transfer (Photo Credit: Aldona Griskeviciene/Shutterstock)
Fungi That Can Consume Radiation
Fungi are not far behind bacteria in their ability to mitigate radiation.
The authenticity of this evidence is derived directly from the core of the forsaken Chernobyl Nuclear Power Plant.
Ten years later, scientists deployed robots to explore the dangerous zone and discovered dark-colored fungi growing on the walls of the destroyed reactor. The study also indicated that these fungi have the ability to decompose the radioactive graphite material from the reactor’s heated core.
It was also observed that the fungi appeared to be moving towards the origin of the radiation, where the radiation levels were highest, almost as if they were attracted to it.
The collected samples revealed the presence of three specific fungal species: Cladosporium sphaerospermum, Cryptococcus neoformans, and Wangiella dermatitidis. All three species exhibited a significant amount of melanin pigment.
Melanin is found in the human skin and is recognized for its ability to absorb light while expelling radiation.
Nevertheless, in these types of fungi, the pigment performs the function of absorbing radiation, enabling it to be harnessed for the purpose of growth. This process is comparable to the way in which plants utilize the pigment chlorophyll to convert sunlight into energy through photosynthesis.
The fungi that contain melanin also experienced faster growth when exposed to radiation, in contrast to other fungi without melanin. This was because the radiation caused a modification in the structure of the melanin molecule, resulting in a fourfold increase in its efficiency in performing a common metabolic reaction.
Within the confines of Reactor 4 in Chernobyl, a total of 37 types of fungi have been discovered. Among these, Penicillium hirsutum, Cladosporium sphaerospermum, Aureobasidium pullulans, and Aspergillus versicolor are believed to be capable of breaking down highly radioactive materials.
The Potential Benefits of Microbes
Aside from their role in bio-remediation, the radiation-tolerant fungi found in Chernobyl may offer a solution to NASA’s radiation challenge. NASA has made it clear that they plan to send humans to Mars, but protecting astronauts from radiation poses a significant challenge.
Humans are unable to survive in space, on the Moon, or on Mars without the Earth’s atmosphere and magnetic field protecting them. As a result, scientists are actively searching for practical methods to shield astronauts.
The International Space Station (Photo Credit : Dima Zel/Shutterstock)
In an effort to find a solution, researchers from the Jet Propulsion Laboratory sent eight species that were isolated from Chernobyl to the International Space Station (ISS). While on the ISS, astronauts discovered that the fungi were able to reduce radiation levels by approximately 2%. Although this alone is not enough to provide complete safety, it does serve as an indicator of what the future may hold. Astronauts could potentially bring a small amount of the fungal colonies on board the rocket and then cultivate them on a shield structure upon reaching Mars. As the colonies grow thicker, they could serve as an affordable additional layer of protection.
It is evident that microorganisms offer a long-term solution to the increasing amount of radioactive waste. Numerous research projects are currently identifying new microorganisms with the ability to metabolize radioactive substances. With these recent discoveries, it is only a matter of time before a microorganism is tasked with the responsibility of cleaning up the radioactive waste produced by every existing nuclear power plant!