On the International Space Station (ISS), space lettuce has become a popular food among astronauts. They even chew on a patch of red leaf lettuce that they grow themselves, as well as enjoy the lush greens in a space garden called Veggie.
But researchers have found that lettuce grown on Earth in a microgravity simulation is more prone to E. Coli and Salmonella illnesses than lettuce produced in space, so it might not be as safe for astronauts.
According to a recent Scientific Reports publication, a team of scientists spun plants in a clinostat—a contraption similar to a rotisserie chicken—in order to cause the plants to lose their sense of direction, as reported by Gizmodo.
According to a statement from Noah Totsline, the lead author of the new work, “in effect, the plant would not know which way was up or down.” “We were kind of confusing their response to gravity.”
Because of gravity-sensing cells in their roots, plants grow downward while growing upward. Nevertheless, the plant’s inherent defense against stresses is less effective in microgravity situations.
The microscopic pores in leaves and stems called stomata aid in breathing and close in response to microbial stresses. According to the research, plants lost their orientation during their carnival trip on the clinostat and opened their pores when bacteria were present.
“The fact that they were remaining open when we were presenting them with what would appear to be a stress was really unexpected,” Totsline stated.
The experiment led the researchers to the conclusion that under simulated microgravity environments, such as the one on the International Space Station, germs such as Salmonella can more easily infiltrate leaf tissue.
According to a 2020 study, the first crop of lettuce to be cultivated on the International Space Station (ISS) between 2014 and 2016 had greater amounts of microorganisms in it while having the same nutrient content as the Earth type.
The ISS’s closed-air atmosphere and astronauts residing in its headquarters may expose plants to viruses despite efforts to lessen microgravity. This could have an impact on the Veggie system, which provides a wholesome food source for upcoming trips to the Moon or Mars.
In order to lower the risk of bacterial illnesses for astronauts munching space lettuce, researchers are suggesting altering the genetic makeup of the plant.
Several lettuce cultivars are presently being tested in a microgravity simulation environment.
