Researchers from the United States and India working with NASA have now discovered four strains of bacteria living in different places in the ISS – three of which were, until now, completely unknown to science.
The team called the new species Methylobacterium ajmalii after renowned Indian biodiversity scientists Dr Ajmal Khan, in a study published in Frontiers in Microbiology.
The four strains belong to a family of bacteria found in soil and freshwater; they are involved in nitrogen fixation, plant growth and can help stop plant pathogens. Basically, good bacteria to have if you grow things.
You might be wondering what these soil bacteria were doing all along the ISS, but the astronauts living on the space station have been growing small amounts of food for years, so it’s no surprise we found microbes of plant origin on board.
The new bacteria were identified from samples taken from various locations inside the ISS. One was discovered on a dining table; another on a hanging panel in a research area used to study low gravity; the third in the Cupola observatory. The fourth species, which was already known, was found on an old air-purifying filter, which had been returned to Earth.
It is highly likely that they were transferred to the ISS from Earth – rather than space – and either survived since the station’s inception or were introduced when new astronauts or payloads arrived.
There’s a lot more research to be done here – the researchers admit they’ve barely scratched the surface of microbial diversity on the space station. About 1,000 samples have already been collected from the ISS, but are still awaiting a return to Earth.
Just imagine the exciting space microbes we haven’t discovered yet!
The research was published in Frontiers in Microbiology.