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Bioremediation of radioactive waste from the sea using deinococcus radiodurans

Bioremediation against nuclear radiation The solution of the future Our cities keep on becoming larger and larger, resulting in an increasing energy demand.

  1. The best known nuclear disaster in history took place in 1986, when one of the nuclear reactors of Chernobyl exploded.
  2. Daly and Minton [13], however, observed that the damaged cells began to grow immediately after irradiation and before recA could be activated, leading them to postulate that a single-strand annealing process occurs before recA expression.
  3. Humans check out at 10 Gy.
  4. The bug can survive doses of radiation up to 10,000 Grays Gy --a level lethal to other bacteria and indeed most cells in general. The disparity has nothing to do with how bacteria protect their DNA, as most researchers had thought.
  5. The insight challenges conventional understanding of radiation damage, hints at new ways to cleanup radioactive waste, and offers the hope of safer forms of radiation therapy.

One of the current solutions for this situation is the building of nuclear plants, which provide us with energy.

Besides all the benefits, these plants entail major disadvantages as well. The disasters at Chernobyl and Fukushima show that ionising radiation can cause major damage to organisms and the environment. Ionising radiation is a form of radiation which is capable of exciting or ionising atoms by transferring energy.

Our environment is not only being polluted with radioactive waste during nuclear disaster, but on a smaller, continuous scale as well. Radioactive waste is constantly being formed in power plants, research, medical care and other industries.

Preventing this pollution is important, but so is removing it. This is where biology could come to the rescue. One of the approaches currently studied is bioremediation, the removal of pollution from the environment with the help of organisms.

  • In 1986, Hensel and colleagues related members of the thermophilic genus Thermus [6] to Deinococcus on the basis of similar 16S rRNA and a shared peptidoglycan structure [7];
  • This ionisation can break chemical bonds and cause the formation of free radicals 7;
  • Some of them can endure extreme cold, heat, salinity, or pH conditions.

Nuclear power plants might be the solution for the increasing energy demand, but bioremediation could be the solution for the potential collateral damage they cause. Nuclear disasters Nuclear disasters can cause widespread pollution and havoc.

The best known nuclear disaster in history took place in 1986, when one of the nuclear reactors of Chernobyl exploded. Large amounts of radioactive products were released directly into the environment, adversely affecting many people due to radiation exposure. It is unclear how many people died from the direct effects of radioactivity exposure, but an immense area became uninhabitable as a consequence of the contamination with nuclear waste 1; 2.

Nuclear waste is similar to other sorts of waste, except for the fact that it often consists of heavy metals and is a source of ionising radiation.

Unfortunately, the Chernobyl accident was not the only nuclear disaster. Similar nuclear accidents occurred in Fukushima in 2011, Three Mile Island in 1979 and Tokaimura in 1999 1. But the problems are not limited to the land.

  1. Cleaning sites containing radioactive waste is incredibly dangerous not only due to the radiation, but also due to the toxic metals that are often involved in radioactive processes.
  2. In 1986, Hensel and colleagues related members of the thermophilic genus Thermus [6] to Deinococcus on the basis of similar 16S rRNA and a shared peptidoglycan structure [7].
  3. Brooks and colleagues [4] found that the radiation-resistant strains also grouped together in terms of cell wall structural profile, growth capacity under certain conditions and fatty acid content. Studies have shown that the metal can increase the ability of the enzymes to fix broken chromosomes, he points out, and its high levels in D.

The contamination of the earth's water bodies is another cause for alarm. Nuclear power plants often generate radioactive wastewater containing heavy metals 3.

  • Similar nuclear accidents occurred in Fukushima in 2011, Three Mile Island in 1979 and Tokaimura in 1999 1;
  • Introducing the wild-type recA led to recovery of radiation resistance [12].

Toxic concentrations of these metals accumulate in living organisms, since heavy metals are not biodegradable. While heavy metals are intrinsically toxic, radioactive heavy metals are even worse 3,4.

Bioremediation against nuclear radiation

Moreover, the half life of radioactive materials like uranium-238 is extraordinarily long; about 4500 million years 5. This means that not only the areas around the power plants are being polluted, but also areas within our own cities. Let us take a look at what radioactivity actually is. Radioactivity can be defined as the spontaneous decay of a radionuclide, which is a synonym for a radioactive isotope, accompanied by the emission of ionising radiation.

Bioremediation of radioactive waste from the sea using deinococcus radiodurans

This form of radiation is capable of exciting or ionising atoms by transferring energy. When energy is indirectly passed on through rays which are absorbed by the atoms of the matter, it is called electromagnetic radiation. In particulate radiation, conversely, electrons are dislodged when charged particles directly hit atoms with kinetic force.

Although the methods by which the energy is transferred differ, both types of radiation cause the atoms to become ionised. This ionisation can break chemical bonds and cause the formation of free radicals 7.