MICROBES IN INTERNATIONAL
SPACE STATION
By:- Farman khan
Strictly speaking that isn’t true. But cleaning in space isn’t
something that you tend to hear much about, even though keeping the
International Space Station (ISS) spic and span is a top priority for the
astronauts who call it home.
This is because the ISS is a closed system, meaning the air inside
has to be continually recycled. To make sure it stays clean and fresh, the
environmental control systems are packed with air filters to get rid of dust and
germs. The astronauts also have to do cleaning and vacuuming, and it is a
regular part of life aboard the space station.
All of this rubbish has to go somewhere, and normally the space
station just jettisons all its trash in a giant capsule that burns up in the
Earth’s atmosphere. But to researchers, the dust inside the air filters and
vacuum cleaner bags is too valuable to just throw away. Instead it makes its
way back to Earth, where it ends up in the hands of Dr Kasthuri Venkateswaran –
a microbiologist working at NASA’s Jet Propulsion Lab.
Part of Venkat’s job is to monitor the microbes on the space
station, to see if any of them could pose a threat to the astronauts on board.
But it’s also to search for microbial species we’ve never seen before, in the
hope that they may have useful characteristics.
The group has been busy analysing a 40-month-old HEPA filter from
the ISS that was brought back to Earth. HEPA stands for High Efficiency
Particulate Arrester, and these filters are able to trap anything larger than
0.3 microns (0.0003 mm) across, can collect 99.97% of microbes passing through
them. Having travelled to space and back, these filters have to be handled
carefully, to prevent any contamination from terrestrial microbes.
“We have a clean room to open such precious samples,” says Venkat.
“So I opened it here, we collected the debris from the filter paper, and then
carried out a microbial analysis.”
When they looked at the microbes that are orbiting the Earth with
the astronauts, the team found a new species of microbes, and as a tribute to Dr.
APJ Kalam they named this microbe as solibacillus kalamii
They describe their find in
the Society’s International
Journal of Systematic and Evolutionary Microbiology. This new
species looks well adapted to living in the difficult conditions 250 km
above us.
“Solibacillus kalamii actually possesses an extra layer [on its outer
surface] “Certain microbes have an extra layer rich in lipoglycoprotein,
a kind of blanket. This can be used as a protective agent against radiation,
like sun screen.”
We hopes that biocompounds like these could one day be
incorporated into space suits, and provide extra protection for astronauts when
they are outside the space station. The ISS is a great location to look for
compounds like this, as only hardy microbes which adapt to these tough
conditions can survive.
“High radiation, microgravity, high CO2 – these are
conditions that make some microbes perish, but other [tolerant] microbes that
develop adaptive strategies can survive.”
This work was part of a project called MT-1 (Microbial Tracking
1), looking at the surfaces and air supply in the space station for three
consecutive flights.
One of these is called Micro-10, where the group sent the
fungus Aspergillus
nidulans up to the ISS and compared it to one that was grown
here on Earth. The aim is to explore whether microgravity allows microbes to
produce novel compounds that could be used as drugs or within biotechnology.
Another is a project called MT-2, which is looking specifically
for pathogens on board the space station, to understand how microbes may
influence astronaut health.
“In a closed system, the astronauts are constantly shedding
microbes and picking them up – it’s like living in an intensive care unit,”
This kind of microbiological research is especially important for
looking at the effects of long-haul space flight. If we ever do make it to
Mars, the trip would take 6–8 months – it would be a wasted journey if the
astronauts got sick before they arrived.
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