It is a popular belief that MRSA is the most resistant bug around. But is it really? According to the Guinness Book of Records the honor of the most defiant bacteria belongs to the little-known Deinococcus radiodurans, a microbe so tough the scientific community dubbed it “Conan the Bacterium”.

Conan was first isolated in 1956 from a can of meat that was literally bombarded with beyond-fatal blasts of radiation. It was later discovered that it can withstand mind-boggling ionic radiation levels of 15.000 Gy, while the deadly dose for humans is as little as 5 Gy. A large radioactivity release from the Chernobyl reactor core melt in April 1986 (approx. 300 Gy) would have felt like a slight summer breeze to D. radiodurans. Its Latin name does not translate to “terrible radiation-resistant grain” for nothing.

Its ability to survive is mainly attributed to its exceptional DNA repair mechanisms, capable of fixing both single- and double-stranded DNA breaks at unmatched efficiency. Its remarkable radioresistance even got Russian and American scientists speculating it evolved through a past life on Mars.

If that alone is not impressive, D. radiodurans has also been reported to endure extreme cold, vacuum, ultraviolet light, extreme dryness and oxidative and reductive stress with ease. It is fair to say even mighty Conan the Barbarian would think twice before messing with his microbial counterpart.

Find out more about this fascinating microbe in the video bellow!


By Luka Zupančič, MSc, University of Applied Sciences Technikum Vienna