EVALUATING THE MICROBIAL ENVIRONMENT ABOARD THE ISS TO ENABLE AN OPTIMIZED MICROBIOME FOR DEEP SPACE HUMAN EXPLORATION

摘要

The recent advent of high-throughput DNA sequencing technologies has allowed for unprecedented insight into various microbiomes, including those on occupied spacecraft. However, no standards currently exist to characterize a "healthy" or "unhealthy" microbial community in this environment. This paper describes methods that can be used in the future to characterize and identify microbial communities and functions in dust found aboard the International Space Station. Chamber studies can be used to consider the impact of moisture on population dynamics that could occur in long-duration spaceflight. This can be coupled with DNA sequence-based approaches to characterize microbial communities under different environmental conditions. In addition to the biological information derived, we can also elucidate valuable engineering-design information which can lead to the future development of microbial standards for spacecraft, to avoid microbial-induced hardware corrosion as was seen on the space station Mir. In addition to mitigating exposure to unhealthy organisms, this knowledge will lead to the determination of criteria for curating a healthy spacecraft microbiome in future long-duration human spaceflight. This may be more sustainable than relying on sterilization to avoid pathogens or other unwanted microbes. Eventually, operating as a long-term, completely automated "Microbial Observatory," these results will provide a long-baseline approach to learning how these microbial communities in low-gravity, higher radiation, and closed-loop environments may influence crew health, with applicability to terrestrial environments such as submarines, aircraft and ships. Finally, we assess how to develop improved microbial clearance protocols that are more relevant to astronaut health, planetary protection, and spacecraft integrity.