Salad may no longer be a healthy option for astronauts in space, a new study has revealed.
Research shows that space salad is riddled with salmonella and could make astronauts very sick.
This is because weightlessness makes plant pores open to bacteria, whereas on Earth they would close.
It’s been more than three years since space-grown lettuce was made an item on the menu for astronauts aboard the International Space Station (ISS).
The salad is grown from control chambers aboard the ISS that account for the ideal temperature, amount of water and light that plants need to mature.
Researchers from the University of Delaware replicated these conditions to see just how healthy this space salad really is.
They discovered that plants grown under manufactured microgravity were more prone to infections from Salmonella.
This is because the Stomata, the tiny pores in leaves and stems that plants use to breathe, open in response to bacteria rather than closing like they do on Earth.
Lead author and university alumnus Noah Totsline said: “The fact that they were remaining open when we were presenting them with what would appear to be a stress was really unexpected.”
With billions of dollars poured into space exploration each year by NASA and private companies like SpaceX, some researchers are concerned that a foodborne illness outbreak aboard the International Space Station could derail a mission.
To try and combat the issue the researchers provided the plants with a helper bacteria called B. subtilis UD1022, which helps protect Earths plants against salmonella.
However, results published in Scientific Reports show that the bacteria could not help the leaves in the space simulator and failed to protect them at all.
Professor Harsh Bais said: “The failure of UD1022 to close stomata under simulated microgravity is both surprising and interesting and opens another can of worms.
“I suspect the ability of UD1022 to negate the stomata closure under microgravity simulation may overwhelm the plant and make the plant and UD1022 unable to communicate with each other, helping Salmonella invade a plant.”
According to NASA, around seven people at a time live and work on the International Space Station.
They noted that it is around the size of a six-bedroom house and is likely a place where germs can wreak havoc.
Professor Kali Kniel added: “We need to be prepared for and reduce risks in space for those living now on the International Space Station and for those who might live there in the future.
“It is important to better understand how bacterial pathogens react to microgravity in order to develop appropriate mitigation strategies.”
The researchers believe that getting safe salad in space is important as not only could salmonella ruin a mission but, with a rapidly growing population on Earth and loss of agricultural land, it is becoming more likely that humans will one day move to space.
Professor Bais added: “You don’t want the whole mission to fail just because of a food safety outbreak.
“People are going to soon think seriously about alternate habitation spaces. These are not fiction anymore.”
The team conclude that to get this ‘rocket salad’ to be safe to eat they may need to tweak plants’ genetics to stop them opening their stomata in space.
Professor Bais’ lab is already taking different lettuce varieties that have different genetics and evaluating them under simulated microgravity.
He said: “If, for example, we find one that closes their stomata compared to another we have already tested that opens their stomata, then we can try to compare the genetics of these two different cultivars.
“That will give us a lot of questions in terms of what is changing.”
Produced in association with SWNS Talker
“What’s the latest with Florida Man?”
Get news, handpicked just for you, in your box.