The world’s hardiest bacteria

Did you know

A tiny bacteria, about the tenth of human hair, holds a place in The Guinness Book of World Records as the world’s toughest bacteria. It’s harmless to humans but loves living in the extremes. Deinococcus radiodurans, or the “terrible berry”, is a hardy bacteria that is a polyextremophile — an organism that can survive in harsh environments. It can tolerate an acute dose of ionising radiation, about 1,000 times more than what humans can.

Deinococcus radiodurans was accidentally discovered in 1956 when scientists were experimenting with using gamma rays to sterilise tinned meat. The meat went bad despite using high doses of radiation and scientists realised it was the bacteria’s doing. This bacteria is found in soil, animal faeces, sewage, dust, clothes, and processed and dried foods.

The secret to its hardiness lies in the multiple copies of genes found in the bacteria and a rapid DNA repair mechanism they have in the cells.

Experiments on the International Space Station have found that D radiodurans can survive in outer space for at least three years and possibly even longer. Scientists are even planning to send them to Mars to explore how habitable the planet is.

On Earth, scientists have created different strains D radiodurans to work in environments contaminated with nuclear radiations. One such strain can consume and digest chemicals like toluene, and heavy metals like mercury in radioactive environments and detoxify them. Scientists are also studying how the bacteria repairs its DNA to find cures to cancer and even ageing, which are caused due to DNA damage resulting from free oxygen molecules—something the bacteria seem to easily get rid of.

Spoorthy Raman