And it's revealed here. And Deinococcus radiodurans and other resistant organisms, even with a large dose of radiation of 4 kilograys, their proteins do not oxidate and remain active and are able to repair the damage on the DNA.
There are other things being produced. And Deinococcus is as resistant as E. coli.
There are other things being produced. Even Deinococcus will die if the dose is high enough, because of this type of damage that is not trivial to repair.
There are other things being produced. In the case of Deinococcus radiodurans, since they are very efficient at repairing DNA damages, it's hard to get mutants for Deinococcus radiodurans, which
And so no one was actually that interested in their lives and behavior until a scientist named Bob Bakker in the '60s started to describe dinosaurs, and in particular one famous dinosaur named deinonychus, and realized that it moved quickly, it was very active, it was very energetic. And this actually became the whole view of dinosaurs that we now know.
So this is a very interesting line of research that could benefit future astronauts going to Mars. But that brings the question of whether Deinococcus radiodurans is is the last frontier of radiation resistance. All of this is based on Deinococcus radiodurans and a few other biological models.
But that brings the question of whether Deinococcus radiodurans is is the last frontier of radiation resistance. All of this is based on Deinococcus radiodurans and a few other biological models. And the question we have is whether there are other biological models available in nature that we don't know yet.
And then after isolating these organisms, we cultivated them individually, and exposed to another round of radiation, and generated this continuum of radiation resistance compared to Deinococcus radiodurans up there, which survives 100% to this dose and E. coli at the bottom here.
So there are different things contributing for radiation resistance. As an example, Deinococcus radiodurans, the biological model for radiation resistance, shares a large part of its gene pool with Thermus thermophilus. And yet Thermus thermophilus is very sensitive, while Deinococcus is very resistant to radiation.
So then we did survival curves with the most radiation resistant ones. And we actually found one organism more resistant than Deinococcus radiodurans, which is this one in red compared to Deinococcus radiodurans in blue. So the question whether Deinococcus is the last frontier?
There are other things being produced. And in fact, Deinococcus radiodurans is specialized in double-strand break repair.
There are other things being produced. But it's very interesting to know that Deinococcus does that within four hours.
And as I said, I'm particularly interested in the organisms that can resist high doses of radiation, both ionizing and non-ionizing radiation. And one of the most studied biological models for radiation resistance is Deinococcus radiodurans. There are other biological models, but Deinococcus is by far the most studied, the most characterized.
And one of the most studied biological models for radiation resistance is Deinococcus radiodurans. There are other biological models, but Deinococcus is by far the most studied, the most characterized. And I use these organisms as a reference in my studies.
As an example, Deinococcus radiodurans, the biological model for radiation resistance, shares a large part of its gene pool with Thermus thermophilus. And yet Thermus thermophilus is very sensitive, while Deinococcus is very resistant to radiation. So clearly, there are physiological factors affecting radiation resistance.
And if you pass a line through the level of radiation that kills 90% of the population, this is a logarithmic scale. So this is the dose that kills 90% of a population of Deinococcus. And these are the values for each one of these survival curves.
And we actually found one organism more resistant than Deinococcus radiodurans, which is this one in red compared to Deinococcus radiodurans in blue. So the question whether Deinococcus is the last frontier? Probably not. Probably there are other organisms more resistant than Deinococcus in nature and that we just didn't discover yet.
But these ones, it's truly more resistant, because it doesn't form cell clumps, and it produces a very light pink pigment. But when we did radiation with gamma rays, Deinococcus is still much better at repairing double strand breaks and the damage caused by high-energy radiation. But still, the discovery of these organisms and a few others very resistant to radiation,
There are other things being produced. So it's very amazing how efficient is the DNA repair mechanism from Deinococcus radiodurans.
There are other things being produced. Actually, there are ways of getting mutants of Deinococcus.
radiodurans in blue. So the question whether Deinococcus is the last frontier? Probably not. Probably there are other organisms more resistant than Deinococcus in nature and that we just didn't discover yet. This is another organism called Geodermatophilus.
There are other things being produced. But I think they would be as resistant or very close to what I've shown here to Deinococcus and all the other organisms.