Studying the effects of microgravity on these fungi may lead to new radiation therapies.
SpaceX and NASA are ready to send the next cargo resupply mission to the International Space Station, which contains over 250 different research investigations that the space station crew will carry out over the next few months. Tucked in among the various experiments are several strains of fungi straight from the world's worst nuclear disaster: Chernobyl.
Thirty years ago, on April 26, 1986, technicians at Chernobyl's infamous reactor number four were conducting routine systems testing when the reactor was struck by an unexpected power surge. This led to a chain of events that ultimately caused a complete meltdown, which blanketed the surrounding area in harmful radiation.
As a result, the Chernobyl nuclear disaster turned the area into a barren wasteland. During the incident, scientists estimate that the power plant released as much radioactive material into the environment as 400 atomic bombs, like the one that devastated Hiroshima, Japan.
Three decades later we are still witnessing the damaging effects of radiation exposure in local wildlife, plantlife, and residents of neighboring areas. However, among all the devastation, scientists are starting to see a glimmer of hope.
Like a phoenix rising from the ashes that once was Chernobyl, several species of fungi were the first organisms to spring up, and are actually thriving in the radiation-soaked environment. These hearty extremophiles could be the key to developing new radiation therapies.
Kasthuri Venkateswaran (Venkat for short), a senior research scientist at NASA's Jet Propulsion Laboratory, is leading the charge to send colonies of these fungi up to the space station.
Samples of the Chernobyl fungi were collected at the site of the accident and at an area outside the fallout zone. Upon inspection, scientists noticed that a portion of the species collected at the site were not only thriving but actually growing towards the radiation.
"Berkeley National Lab has an agreement that allows them to collect samples from the Chernobyl accident site," explained Venkat. "Following the accident, fungi were the first organisms to pop up and scientists wanted to understand how they can thrive in such an environment."
Venkat and JPL are just one part of a multi-institutional partnership that proposed this study, which aims to better understand how the fungi shield themselves from radiation into order to survive. The team thinks that melanin, the same dark pigment we have in our skin, helps to shield the fungi from harmful radiation and helps convert that radiation into a food source.
"The fungi collected at the accident site had more melanin than the fungi collected from outside the exclusion zone," Venkat said. "This means the fungi have adapted to the radiation activity and as many as twenty percent were found to be radiotrophic—meaning they grew towards the radiation; they loved it."
Observable molecular changes within the fungi were isolated to the species collected at and around ground zero. This tells researchers that these changes were brought about by cellular stress from the radiation. They want to duplicate this process to see if new drug therapies can be derived from the fungi.
To do so, eight different species of fungi (seven from Chernobyl and one previously grown on station) will be exposed to the stresses of microgravity. The fungi colonies will grow on board the ISS for 14 days, before being returned to Earth. After the samples are returned to JPL, Venkat and his team will compare them to identical strains of fungi grown on the ground.
"We are sending these fungi to the space station because they are shown to produce special biological molecules that have potential to fight illnesses such as depression and cancer," Venkat said.
But that's not all.
The research also has agricultural benefits. By understanding what genes are responsible for the molecular changes, scientists can help engineer crops that are better suited to extreme climates, like those in arid climates and even on other planets.
The world's space agencies have their sights set on Mars, and as we move towards exploring the Red Planet and other worlds in the Solar System, having radiation-resistant plants will be a huge plus.