While growing fresh greens in orbit appears beneficial for the health of spacefarers, recent research from the University of Delaware reveals a potential risk.
Engineer Daniel Schubert holds lettuce at the German Aerospace Center on July 21, 2014 in Bremen, Germany.
Space Salad Risks: Microgravity Boosts Salmonella Vulnerability
The study, titled "Simulated microgravity facilitates stomatal ingression by Salmonella in lettuce and suppresses a biocontrol agent" published in Scientific Reports, reveals that when leafy plants like lettuce and spinach are grown in space, they become more susceptible to Salmonella enterica pathogen, raising concerns for the well-being of astronauts.
Despite the nutritional benefits of space salad, the presence of bacteria creates challenges for maintaining a healthy environment during prolonged space missions. This finding underscores the crucial need to comprehend and address potential health risks associated with cultivating food in the distinct conditions of space.
The International Space Station (ISS) is known for hosting aggressive bacteria and fungi, and the possibility of these space microbes causing widespread sickness among astronaut crews poses a serious threat to lives.
Plant biologist Harsh Bais and his team conducted experiments using a clinostat, simulating microgravity conditions, to investigate the effects of S. enterica bacteria on lettuce plants. Surprisingly, the stomata pores in the lettuce, designed to keep out harmful invaders, opened up, allowing the bacteria to invade, indicating a compromised defense mechanism in microgravity.
Further experimentation introduced a beneficial bacteria species, known for protecting plants from external stressors. Despite its typically defensive role, the plant's defenses failed in microgravity, suggesting a disruption in the usual chemical reactions that would safeguard the lettuce.
The unexpected behavior of the stomata, remaining open when faced with stress, indicates confusion in the plant's response to gravity, emphasizing the complexity of growing plants in space environments.
READ ALSO: Microgravity Refrigerator Could Store Food for Astronauts in the Future
Addressing Challenges in Space Agriculture: Implications, Risks, and Solutions
The potential impacts of the new study by the University of Delaware researchers on space-grown plants extend to outer space cohabitation and address Earth's challenges. As concerns about food safety and security intensify, given the projected global population of 9.7 billion in 2050 and 10.4 billion in 2100, the urgent need for alternative habitation spaces becomes evident.
The frequent recalls of Earth's lettuce due to contamination risks like E. coli or Salmonella highlight the critical importance of ensuring the safety of space-grown leafy greens, a preferred food for astronauts. The fear of a mission failure due to a food safety outbreak underscores the significance of addressing these challenges in space agriculture.
While sterilized seeds are a starting point, the space environment still poses risks of microbial contamination. Scientists, led by plant biology professor Harsh Bais, suggest exploring genetic modifications to prevent plants from widening their stomata in microgravity, a factor enabling bacteria to enter.
Actively evaluating different lettuce varieties with diverse genetics under simulated microgravity, Bais's lab aims to understand and potentially mitigate these challenges, paving the way for safer and sustainable space agriculture.
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