UAH researchers, led by Dr. Yo-Ann Velez Justiniano and Dr. Tanya Sysoeva, began the project several years ago to combat obstructive biofilms in the ISS Environmental Control and Life Support Systems (ECLSS). These biofilms can clog water systems and threaten crew health. The GEM-B2 experiment investigates bacterial conjugation-a process in which DNA elements called conjugative plasmids transfer from one bacterium to another. This horizontal gene transfer is a key mechanism in the spread of antimicrobial resistance among human pathogens.

The ECLSS ISS Urine Processor Sustaining Lead, Jonathan Wilson of NASA MSFC, received a grant under NASA's POLARIS Program to lead the multi-institutional collaboration. At UAH, the Sysoeva Lab optimized the experiment by selecting appropriate bacterial strains and conjugative plasmids to measure gene transfer differences between Earth's gravity and the microgravity conditions aboard the ISS.

Researchers considered factors such as bacterial concentration, cold storage transport, and how these affect bacterial viability and gene transfer efficiency. "Conjugative plasmids tend to spread genes converting bacteria into antibiotic resistant strains, and thus are the main mechanism of the current global spread of antimicrobial resistance in human pathogens that we study in our group," Sysoeva said. "This is a unique opportunity for us to continue mechanistic characterization of this fundamental process of gene transfer under reduced gravity conditions at ISS to add to the basic understanding as well as make the first steps to implement this knowledge in remediation strategies."

While Earth-based studies suggest that biofilms might encourage gene transfer through conjugation, the GEM-B2 experiment will determine how microgravity influences this process. The aim is to develop effective bioremediation methods to reduce or eliminate biofilm formation inside the ISS water systems and future habitats like the Artemis Lunar Gateway.

The Sysoeva Lab, in collaboration with its partners, conducted a mock validation trial on the ground to simulate the ISS conditions for the GEM-B2 payload, ensuring temperature and timing closely match those in orbit.

Elanie Briggs, a Ph.D. student in the Biotechnology Science and Engineering program at UAH, said, "For me, this whole experience has felt surreal. My earliest memories of space were simply stargazing with my dad at distant planets through his telescope. Space science and exploration always seemed far removed from my scope. In my early academic years, I assumed my path would lead me to just be another scientist producing good work but blending into the background of scientific progress." She now feels she is "helping to push the limits of space biology."

Amy LeBleu-DeBartola, another Ph.D. student in the BSE program at UAH, shared a similar sentiment. "I have been fascinated by space for over 18 years now," she said, reflecting on an early visit to Huntsville and Space Camp. "Being able to be a key member of the science team on an ISS payload this early in my career is astounding," she added, emphasizing her role in the ground validation experimental design.

Research Report:Genetic Exchange in Microgravity for Biofilm Bioremediation (GEM-B2)

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