In the 1950s, scientists exposed a tin of meat to a dose of radiation that they expected would kill all forms of life. But, to their surprise, they discovered a surviving microorganism: the bacteria Deinococcus radiodurans.
Deinococcus radiodurans has long been known for its astounding radiation resistance. It's able to withstand radiation doses more than thousands of times higher than what it would take to kill a human being, earning it the nickname "Conan the Bacterium."
Ever since its discovery, scientists wondered: Why exactly is Deinococcus radiodurans so resilient against radiation?
In a study published in the journal Proceedings of the National Academy of Sciences this week, researchers finally home in on an answer.
Three components found in a Deinococcus radiodurans cell — manganese ions, phosphate and peptides — come together to create a very powerful antioxidant that is more resistant to radiation than researchers expected.
Study co-author Brian Hoffman, a chemist at Northwestern University, says that prior to the study, he thought the answer would be a simple math problem: Add the radioactive resistance of each component and get the total amount of radioactive resistance the overall bacterium had.
But the results surprised him.
"Oh my God," he recalls thinking. "There's something new that forms when you put the pieces together, which makes it better than one or the other. It's the combination [in which] they interact with each other!"
In other words, the interaction between these three components is greater than the sum of its parts.
"We now have a much better understanding of the nature of the complex and how it is formed, which means we can now try and think of ways of making them better," says Michael Daly, a professor of pathology at Uniformed Services University. Daly has studied Deinococcus radiodurans for decades and is a co-author on the paper.
The researchers hope this that with this new understanding of Conan the Bacterium's resistance to radioactivity, "better" might eventually mean innovations to protect humans from radiation while exploring deep space or radiological emergencies here on Earth.
Want more stories about the microbial world? Email us at shortwave@npr.org — we'd love to hear your thoughts!
Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.
Listen to Short Wave on Spotify and Apple Podcasts.
This episode was produced by Rebecca Ramirez and Jordan Marie-Smith. It was edited by Rebecca Ramirez and Christopher Intagliata. Tyler Jones checked the facts. The audio engineer was Gilly Moon and Ted Mebane.
Copyright 2024 NPR
