Four strains of bacteria have been found on the space station, three of which were previously unknown to science. They can be used to help grow plants during long-term spaceflight missions in the future.
The space station is a unique environment in that it has been completely isolated from Earth for years, so a multitude of experiments have been used to investigate what kind of bacteria are present there.
Eight specific spots on the space station have been continuously monitored for the presence of microbes and bacterial growth over the past six years. These areas include modules in which hundreds of scientific experiments are conducted; a growth room where plants are grown; as well as places where the crew gathers for meals and other occasions.
As a result, hundreds of samples of bacteria have been collected and studied, and another thousand are waiting to return to Earth for analysis.
The four strains of bacteria that researchers isolated belong to the Methylobacteriaceae family. The microbes were taken from space station samples during the successive expeditions of different crews.
Methylobacterium species are useful for plants, promote their growth and fight pathogens, among other things.
One of the strains, Methylorubrum rhodesianum, was already known. But the other three rod-shaped bacteria were unknown – although scientists could determine by genetic analysis that they were the most closely related to the bacterium Methylobacterium indicum.
Senior research scientist Kasthuri Venkateswaran and planetary protection engineer Nitin Kumar Singh, both at NASA’s Jet Propulsion Laboratory in Pasadena, California, worked on this research to understand the potential uses of the bacteria.
The new strains may be “biotechnologically useful genetic determinants” to aid in plant growth in space, the scientists said in a statement. “To grow plants in extreme places where resources are minimal, isolation of new microbes that promote plant growth under stressful conditions is essential.”
Leafy greens and radishes have been successfully grown on the space station, but growing crops in space is not without its problems. Methylobacterium can be used to help plants overcome the stressors they face when trying to grow outside of the earth.
However, the researchers stressed that only time, and experiments with this bacteria to test their theory, will tell if it works.
The researchers also want to know more about these newly found bacteria.
“Since these three ISS strains were isolated at different time periods and from different locations, their persistence in the ISS environment and ecological significance in the closed systems warrant further investigation,” the authors wrote in the study.
Until humans reach Mars, the space station will serve as a testbed for a host of technologies and resources needed for long-term missions into deep space, the researchers said. This includes the study of microorganisms and how they affect life on the space station – and how they can be used.
“Because our group has expertise in culturing microorganisms from extreme niches, we have been commissioned by the NASA Space Biology Program to investigate the ISS for the presence and persistence of the microorganisms,” said Venkateswaran and Singh.
The Methylobacterium discovered during this study is also not harmful to the astronauts.
“Needless to say, the ISS is a neatly maintained extreme environment. Crew safety is a number 1 priority, so understanding human and plant pathogens is important, but beneficial microbes such as these new Methylobacterium ajmalii are also needed. . ”
Given the amount of bacteria found on the space station and still awaiting analysis, and the potential for discovering new strains, the researchers hope that molecular biology equipment can be developed to study the bacteria while they are in the space station.
“Rather than returning samples to Earth for analysis, we need an integrated microbial control system that collects, processes and analyzes samples in space using molecular technologies,” the researchers said. “This miniaturized ‘omics in space’ technology – a development of a biosensor – will help NASA and other space-faring nations achieve safe and sustainable exploration of space for a long time.”