How Fungi Can Support Life in Space

By Allison Lucht and Will Broussard

The year 2021 saw the most successful orbital launches and the most humans in space at any one time. While so many of us are gazing skyward at the possibility of interstellar travel, a few of us are also exploring the potential impact subterranean fungi could have on our ability to boldly go where no one has gone before.

As a companion for space travel, fungi may not be your first choice, but their unique growth habits, high nutritive value, therapeutic benefit, and ability to withstand extreme environments could prove essential to long distance space travel. In fact, mushrooms thrive so well in space many believe them to be of extraterrestrial origin. Earthly or not, we’ll discuss the many ways mushrooms could assist humanity in future space exploration.

Our first hint that fungi could survive if not thrive in outer space came in 1988, when the Russian space station Mir was attacked by what Soviet microbiologist Natalia Novikova later described as an “aggressive space fungus.” Though the threat was serious, the organism was not your typical space invader, but a rapidly growing web of fungal hyphae which was threatening windows, control panels, and gradually eating away at the interior of the space station and a Soyuz transport vehicle. An aggressive daily cleaning regimen finally took care of the problem aboard Mir, which sustained a broken window following the dissolution of a rubber seal.

As one can imagine, decomposing space stations are less than ideal, and although NASA asserted these fungal stowaways were of Earthly origin, their presence in space offered our first opportunity to examine astromycology – the study of earth-derived mushrooms in space – up close and personal. This unique situation proved that mushrooms could survive space travel. That a fungus could spread across an entire space station suggests they may even thrive in outer space. How could this be?

High radiation and zero gravity present challenges for all life forms while in space, be they fungal or human. Despite these obstacles, several saprophytic species – fungi feeding on dead or decaying organic matter - were identified on Station Mir. One might not expect a modern spacecraft would have much decaying matter, but human astronauts shed tens of thousands of dead skin cells daily, even in space. These skin cells could have provided plenty of food for the fungi, which might explain why so many could survive aboard the craft.

Saprophytic fungi are well-known for their ability to survive in a wide variety of climates, including extreme heat and cold. Many are even able to withstand high amounts of radiation, as was the case following the Chernobyl nuclear disaster in 1986. Fungal organisms removed from the wall of the dysfunctional reactor were darkened by natural pigments through a process called melanization. Melanized fungi can be found all over the world, including Antarctica.

Research on the mold Penicillium expansum found that specimens living in space for seven months developed an increased presence of melanin layers due to the increases in radiation. Space-based research into another type of fungal mold, Cryptococcus neoformans found that fungal individuals experiencing melanization grew faster after being exposed to 500 times the background rate of radiation. This suggests that melanin may not only provide protection to fungal DNA from space radiation, but that fungi may be converting the radiation into energy, like the process by which plants convert energy from sunlight.

Fungi and plants are known to grow in reaction to gravity to ensure efficiency for optimal growth and reproduction. Observations made on mushrooms grown in space show that fungi may flourish in the absence of gravity. When fungi reproduce, they release spores into the air, sometimes with force. With no friction in space due to the lack of gravity, the spores simply float away. This could be why astronauts aboard Mir witnessed large, fungal formations seemingly all over the spacecraft.

Photos curtesy of NASA / Ames Research Center / Lynn Rothschild

High incidence of radiation and the prevalence of zero gravity can make space travel for humans quite challenging and downright dangerous. Fungi are not fazed by these setbacks and may even thrive in these conditions. Could fungi be useful in other implications of human space travel? Research suggests it’s quite likely.

When some of us think about fungi, the first thing that comes to mind might be delicious, edible mushrooms. Fungi are in fact nutritionally diverse; rich in protein, complex carbohydrates, and essential vitamins such as D and B.

Mushrooms are also relatively easy to grow and don’t take much time, space, or resources to do so. It’s for these reasons they are being considered as a sustainable food source for space travel. Species under consideration include the oyster mushrooms due to their fast growth rate and high yield of mushrooms.

Photo curtesy of 2018 Stanford-Brown-RISD iGEM Team

In addition to being an excellent source of food, research is being conducted into mycelium-based structures that could be utilized at future space colonies. NASA’s myco-architecture project is currently prototyping technologies that could see mycelium habitats being grown on the moon, Mars, and beyond. The technology would allow future space explorers to travel with a compact, lightweight material alongside a dormant fungus that could be simply unfolded and combined with water to grow a fully functional home.

These myco-structures would not only provide a place for space travelers to rest their heads, but they would also provide essential protection through the unique fungal ability to absorb radiation. Fungi-based living structures may not be what we imagined for the future of space travel; mycelium is not as shiny as the metallic, futuristic cities portrayed in media, but it has the advantage of providing an efficient, safe, and eco-friendly habitat for life in space.

There are roughly 7,520 functional and non-functional artificial satellites in orbit. This number is expected to climb exponentially as telecommunications evolve. This poses many problems, including collision risks, space debris, and environmental impacts. Decommissioned satellites are a major source of pollution as they reenter Earth’s atmosphere and leave behind traces of aluminum and other toxic particles. Accumulation of these substances over decades can lead to ozone depletion among other environmental impacts. It’s for these reasons that satellite engineers and designers are looking to redesign their future satellites, with mushroom mycelium under consideration for future materials.

Using fungi is an inexpensive, durable, and non-toxic solution to the dilemma of satellite overpopulation. Mycelium is extremely tough and durable, can withstand extreme temperatures and radiation, and is even fire-resistant. When future mycelium satellites re-enter our atmosphere, they won’t catch fire or pollute our atmosphere, oceans, or land.

It is clear that fungi can survive surprisingly well in space. High radiation and zero-gravity are harsh on feeble human bodies but mushrooms appear to thrive in this type of environment. Is it possible that fungi are originally from space? Some of us think so.

The theory that mushrooms come from the stars stems from the theory of panspermia, which asks the following question: what if microscopic life forms, such as bacteria, fungal spores, and other microbes, could be transported through space and land on another planet?

Panspermia suggests that fungal spores could have arrived on Earth over a billion years ago by comets, asteroids, or other space debris. This could explain why fungi adapt so well to life in space, but this theory is still unproven. While we wait for the panspermia hypothesis to pan out, it’s a fascinating idea to entertain. Perhaps alien fungi will one day provide the missing link to the origin of life on our planet.

Psilocybin mushrooms, also known as “magic mushrooms,” have gained a lot of attention. They’re currently being studied to treat a wide range of mental health conditions, including depression, anxiety, and post-traumatic stress disorder to name a few. The results of these studies are incredible, with numerous states having already decriminalized or legalized psilocybin for therapeutic use.

Mycologist Paul Stamets is well-known for his advocacy of all mushrooms, including psilocybin. He’s even suggested that psilocybin mushrooms could be an essential part of every astronaut’s psychological toolkit. According to Stamets, psilocybin mushroom use under the right conditions in a therapeutic setting, may help future astronauts become more mentally resilient while they’re on their long journey.

Instead of feeling isolated and depressed due to being so far from home, psilocybin therapy may allow them to feel like they’re part of one big consciousness. Psilocybin may also impart to astronauts an increased focus on their mission and enhanced creativity and problem-solving abilities, attributes valuable both on Earth and in deep space.

Fungi hold the promise for making space exploration more efficient and environmentally friendly. Not only can they nourish our bodies and minds while traveling in space, but they can also provide strong, radiation-proof, non-toxic materials as well. The seemingly endless amounts of ways mushrooms can enhance a human future in space will be added to as research into astromycology continues. We await with bated breath the future of this exciting science!

Would you ever travel to space to stay in a house made of fungi? Tell us in the comments below.

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https://www.sciencedaily.com/releases/2018/10/181025103329.htm