American scientists from the University of Delaware discovered that lettuce grown on the International Space Station (ISS) could be dangerous if consumed with other vegetables. The study was published in the scientific journal magazine Scientific Reports (SciRep).
The team concluded that microgravity on the ISS makes plants more vulnerable to pathogens living on the station. These include microbes that are dangerous to humans, such as E. coli and salmonella.
The study was carried out using a device called a clinostat, which allows simulating weightless conditions for plant organisms. Scientists have found that crops grown outside gravity are particularly vulnerable to salmonella colonization.
Small pores on stems and leaves are called stomata, and plants use these stomata for gas exchange. As a defense mechanism, the pores often close when the plant is exposed to bacteria.
But in microgravity conditions, lettuce bushes for some reason do not close their pores when microbes appear. Therefore, lettuces in space will be much more vulnerable to salmonella than those on Earth.
Experts found that rotating at low speed was enough to confuse the facility’s defense system.
To solve the problem, researchers suggested disinfecting the seeds before sending them into space. Another solution would be to genetically engineer crops to eliminate microgravity’s ability to open their pores wide.
Previous scientists came with A salad recipe that can be made from ingredients grown in space.