October 20, 2000

 

Space Fungus Gets Scientists' Attention

Fungus Is Everywhere  

You might not expect to find mold and mildew in a brand new space station. But that's just what scientists are worried about. What problems can common fungus cause for the next generation of astronauts?

It was a discovery that matched the exotic with the commonplace, the extraterrestrial with the earthly. An astronaut peering out of Russia's Mir space station 12 years ago found the view blocked by a layer of fungus growing on the inside of the window.

The fungus had arrived from Earth, probably attached to the human travelers occupying Mir. As it multiplied rapidly and even began "eating" the equipment on the space station, scientists started thinking seriously about dangers they had not anticipated. Fungus is a part of everyday life on Earth, but who would have thought that it could affect the advanced machinery hurtling through such an inhospitable environment as outer space?

Now, researchers are turning their attention to the $60 billion International Space Station nearing completion and already in orbit. They are hoping to make it more fungus-proof than its Russian predecessor.

  • There are many kinds of fungus we encounter regularly on Earth. In the space below make a list of the ones you know about. (You'll find some additional answers in the Familiar Fungi section of this story.)

Fungi You May Know

 
 

As researchers study the growth of this space fungus, they have realized how it could thrive in the confines of a space station. The moisture produced by the human occupants—whether by breathing, perspiring, or bathing—helps create a friendly environment for microorganisms. These include the Aspergillus, Penicillium, and Cladesporium varieties of fungus commonly found on Earth.

"Microorganisms can grow on everything on Earth or in space," Harvard University biologist Ralph Mitchell told ABCNEWS.com earlier this month. "Because a space station is such a tight space, there can be lots of nooks and crannies where organisms can grow." In the case of Mir, those locations have included the walls, electrical panels, air conditioning, and communications equipment.

 
Lessons from Space  

Fungus is better known for growing on—and feeding off—living or dead organisms, including plants, trees, and humans. The fungus produces enzymes that eat away at these "host" organisms, which in turn provide the fungus with the nutrients it needs to live.

The recent developments in space have helped scientists realize how strongly fungus can attack even inanimate materials such as glass, metal, and plastic.

  • Why do you think fighting fungus is especially important in a spacecraft? What steps would you take to eliminate fungus from a place like a space station?

The scientists studying space fungus have come up with their own answers. Over the long run, uncontrolled fungus can do extensive damage to expensive equipment. And service calls to outer space add even more expense. Of course, if critical systems onboard a space station were damaged, the safety of the crew could become a factor.

Of even greater concern is the potential effect of fungus on the health of the astronauts. In an interview with The Boston Globe, biologist Mitchell noted that spacecraft are "closed systems. Within days, all of the astronauts share all of the same microflora ... like children in a kindergarten."

However, space travelers face more grown-up problems. For starters, the stresses posed by weightlessness, lack of sleep, and the anxieties of space flight affect the immune systems of astronauts. Fungal infections they would fight off on Earth become harder to fight off in outer space.

The higher level of radiation outside of Earth's protective atmosphere increases the likelihood that these fungi can mutate into more powerful forms. Medical researchers even worry about such mutated fungi returning to Earth and affecting public health and agriculture.

So as the International Space Station prepares to receive its first formal occupants in several weeks, efforts are underway to make it a fungus-free zone. And the approaches sound much like those back on Earth:

  • In recent months, astronauts putting the finishing touches on the station removed panels to check for any growth in out-of-the-way places.

  • NASA has also installed a hepafilter—the most advanced air-filtering system made. It is sensitive enough to remove microorganisms from the air. The same kind of filters are being considered for use on commercial airlines.

  • Those living on the space station will have to do more housecleaning than they have in the past.

Find out more in the ABCNEWS.com article, "Space Bugs" and Space.com's Space Fungus: A Menace to Orbital Habitats.

Familiar Fungi  

We have close encounters with fungi on Earth all the time, from bouts with athlete's foot to meals with mushrooms. Here are some fungi you might know:

Fungus

Details

Mold

Check that final slice of bread carefully. This fungus grows best in damp conditions and usually provides a furry surface to affected foods, wood, and plants.

Penicillin

In 1929, Dr. Alexander Fleming revolutionized medicine when he discovered that the penicillium fungus could kill dangerous bacteria. The penicillin that resulted was able to treat a wide range of bacterial diseases.

Yeast
This single-celled fungus has long been used in making bread, beer, and other food products.

Athlete's Foot

This treatable condition, caused by a moldlike fungus called a dermaphyte, has made plenty of people uncomfortable, even if they are not athletes.

Mushrooms

Although many mushrooms are poisonous, they have become perhaps the most recognized species of fungus.

Specialists in the field have identified an estimated 100,000 species of fungus, and almost 1,000 additional species are added to the list every year. And fungus often makes its way into the daily news.

  • Dust blown across the Atlantic Ocean from Africa is believed to contain fungus that has damaged coral reefs in the Caribbean.

  • A controversial attempt is underway to develop a fungus that attacks opium poppies. Supporters of the mutated fungus say it will help to fight the trade in heroin, which is made from poppies. Opponents warn that scientists are creating a potential biological weapon that could spread diseases to many other plants.

  • An unidentified fungus is a leading suspect in the death of thousands of oak trees in California. Fungus has previously killed off many American chestnut and elm trees.

  • A giant fungus in an eastern Oregon forest covers 2,200 acres, is estimated to be 2,400 years old, and is believed to be the largest living organism ever found.

For all the damage that fungi can cause, scientists stress that they are critical parts of the natural food chain and forest ecology. Fungus on trees and plants releases important nutrients into the soil and serves as the food supply for small insects and worms.

 

Learn More

  • Meet one of the first inhabitants of the new International Space Station. Check out the Riverdeep Today article, "What's It Like to Meet an Astronaut?"

  • Could the Mir space station become a vacation resort one day? Read the Riverdeep Today article, "Vacation 200?"

 

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