In order to withstand the rigors of space on deep-space missions, food grown
outside of Earth needs a little extra help from bacteria. Now, a recent
discovery aboard the International Space Station (ISS) has researchers may
help create the 'fuel' to help plants withstand such stressful situations.
Publishing their findings to Frontiers in Microbiology, researchers working
with NASA described the discovery and isolation of 4 strains of bacteria
belonging to the family Methylobacteriaceae from different locations aboard
the ISS across two consecutive flights.
While 1 strain was identified as Methylorubrum rhodesianum, the other 3 were
previously undiscovered and belong to a novel species novel. The rod-shaped,
motile bacteria were given the designations IF7SW-B2T, IIF1SW-B5, and
IIF4SW-B5 with genetic analysis showing them to be closely related to
Methylobacterium indicum.
Methylobacterium species are involved in nitrogen fixation, phosphate
solubilization, abiotic stress tolerance, plant growth promotion and
biocontrol activity against plant pathogens.
Potential for Mars missions
Now, in honor of the renowned Indian biodiversity scientists Dr Ajmal Khan,
the team has proposed to call the novel species Methylobacterium ajmalii.
Commenting on the discovery, Dr Kasthuri Venkateswaran (Venkat) and Dr Nitin
Kumar Singh of NASA's Jet Propulsion Laboratory, (JPL), says that the
strains might possess " biotechnologically useful genetic determinants" for
the growing of crops in space.
However, further experimental biology is needed to prove that it is, indeed,
a potential game-changer for space farming.
"To grow plants in extreme places where resources are minimal, isolation of
novel microbes that help to promote plant growth under stressful conditions
is essential," they said.
Along with JPL, other researchers collaborating on this discovery are based
at the University of Southern California, Los Angeles; Cornell University
and the University of Hyderabad in India.
With NASA one day looking to take humans to the surface of Mars - and
potentially beyond - the US National Research Council Decadal Survey
recommends that the space agency use the ISS as a "test-bed for surveying
microorganisms", according to Venkat and Singh.
"Since our group possess expertise in cultivating microorganisms from
extreme niches, we have been tasked by the NASA Space Biology Program to
survey the ISS for the presence and persistence of the microorganisms," they
add.
"Needless to say, the ISS is a cleanly-maintained extreme environment. Crew
safety is the number 1 priority and hence understanding human/plant
pathogens are important, but beneficial microbes like this novel
Methylobacterium ajmalii are also needed."
Expanding the ISS lab
As part of an ongoing surveillance mission, 8 locations on the ISS are being
monitored for bacterial growths and have been for the last 6 years. These
sample areas include where the crew assembles or where experiments are
conducted, such as the plant growth chamber.
While hundreds of bacterial samples from the ISS have been analyzed to date,
approximately 1,000 samples have been collected from various other locations
on the space station but are awaiting a trip back to Earth where they can be
examined.
According to Venkat and Singh, the eventual goal is to bypass this lengthy
process and potentially find new novel strains using molecular biology
equipment developed and demonstrated for the ISS.
"Instead of bringing samples back to Earth for analyses, we need an
integrated microbial monitoring system that collect, process, and analyze
samples in space using molecular technologies," Venkat and Singh said.
"This miniaturized 'omics in space' technology - a biosensor development -
will help NASA and other space-faring nations achieve safe and sustainable
space exploration for long periods of time."
Reference:
Bijlani S, Singh NK, Eedara VVR, Podile AR, Mason CE, Wang CCC and
Venkateswaran K (2021) Methylobacterium ajmalii sp. nov., Isolated From the
International Space Station. Front. Microbiol. 12:639396. doi:
10.3389/fmicb.2021.639396