• Question: How does Deinococcus radiodurans with stand high levels of radiation?

    Asked by 284bera46 to Colin, John, Kevin, Shikha, Triona on 13 Nov 2014.
    • Photo: Kevin Motherway

      Kevin Motherway answered on 13 Nov 2014:


      You might have heard the phrase “Nature abhors a vacuum”. In other words no matter what the conditions nature will always find a way. Humans have even evolved to be able to live in the vacuum of space (6 months at a time). Bacteria have been found in deep mines living inside rocks 4 km underground. There is always something that will not just survive, but will thrive. Whether its extreme cold, heat or even radiation most life cannot tolerate it but that just leaves all the more room, food and resources for those creatures hardy enough to stand it. That’s what Natural Section or “survival of the fittest is all about. When faced with a challenge those that can survive will then thrive when all the weaklings have been wiped out (thankfully human society isn’t like that!). So while it might look like Deinococcus radiodurans was “designed” to survive, its just that its the one that survived and thrived for that particular niche.

      Deinococcus radiodurans is a very good example of an Extremophile or like the Special Forces of bacteria that can survive in almost any conditions. That means that Deinococcus radiodurans or a bacteria like it is a very good candidate for life on Mars where we have found water!

      Great question, I had to Google what Deinococcus radiodurans was! I’ve been involved with clean ups of oil spills where we deliberately spread extremophile bacteria that just love muching up oil while all the others die out.

    • Photo: Shikha Sharma

      Shikha Sharma answered on 21 Nov 2014:


      Hi 284bera46,

      Deinococcus radiodurans is a bacterium that can live through blasts of radiation thousands of times greater than the level that would kill a human being. Radiation is measured in units called rads. A dose of 500 to 1,000 rads is enough to kill a person. D. radiodurans thrives even after being hit by up to 1,500,000 rads….Isn’t that amazing ??
      D. radiodurans cells have four to ten copies of their DNA molecule. Most bacteria have only one copy. These copies serve as back-ups, kind of like the back-up copies you make of your important computer files in case one day your computer crashes. So when radiation hits and D. radioduran’s DNA gets busted up, the microbe has lots more chances of finding an intact copy of each gene to use as it stitches its DNA back together. A special protein called RecA does the stitching. Also, it appears that D. radiodurans may have more of the cell repair tools that most bugs have. This is the reason why they can stand high levels of radiation. 🙂

Comments