Biologists have found four strains of bacteria from the Methylobacteriaceae family in surface samples collected during Microbial Tracking-1 flight experiments at the International Space Station (ISS).
Transmission electron microscope showing the general cell morphology of Methylobacterium jeotgaliImage credit: Aslam et al., doi: 10.1099 / ice.0.64625-0.
Dr. Kasthuri Venkateswaran of NASA’s Jet Propulsion Laboratory and colleagues analyzed samples collected during Microbial Tracking-1 flight experiments in 2015 and 2016.
“As part of an ongoing Microbial Tracking experiment on the ISS, eight sites are being monitored for bacterial growth and has been happening over the past six years,” they explained.
“These exemplary areas include where the crew meets or where experiments are conducted, such as the plant growth chamber.”
The researchers isolated four Methylobacterium strains – designated IF7SW-B2T, IIF1SW-B5, IIF4SW-B5 and I1-R3 – from the samples.
Of these, the first three tribes were assigned to a new species called Methylobacterium ajmalii, while the fourth was identified as Methylorubrum rhodesianum
“Members of the Methylobacterium genus are Gram-negative, rod-shaped bacteria, ”the scientists said.
“The genus consists of 45 recognized species, which are ubiquitous in a wide variety of habitats, including air, soil, fresh water and sediments, and may be free-form or associated with plant tissues.”
Methylobacterium species are involved in nitrogen fixation, phosphate solubility, abiotic stress tolerance, plant growth promotion and biological control of plant pathogens, ”she added.
“For example, a recently discovered Methylobacterium sp. 2A was found to result in higher side root density in inoculated potato crops, even under conditions of salt stress, compared to control plants not inoculated with the bacteria; it was also found to exhibit biocontrol activity against various plant pathogens. “
According to the team, the newly isolated strains could have “biotechnologically useful genetic determinants” for growing crops in space.
However, more 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 new microbes that help promote plant growth under stressful conditions is essential,” the authors said.
The findings appear in the journal Frontiers in Microbiology
Swati axani et al Methylobacterium ajmalii sp. Nov., isolated from the International Space Station. Front side. Microbiolpublished online March 15, 2021; doi: 10.3389 / fmicb.2021.639396