Unlocking the microbiome of the International Space Station

The microbiome of the International Space Station (ISS) has been monitored to assess risk to spacecraft and crew for 22 years. This monitoring has been achieved through onboard culture and ground-based analyses with bias toward the detection of culturable organisms depicting generally low biodiversity. The implementation of culture-independent, nanopore-based studies, both onboard the ISS and with returned samples, is revealing a more thorough depiction of the microbiome. There is a common core microbiome across time and location, but key distinct areas of greater diversity exist. Through further investigation, these areas are emerging as unique ecological niches, potentially resulting in environmentally driven microbial selection. Moreover, the presence of some noted taxa has implications for crew health, planetary protection, and controls in future spacecraft systems. The ability to perform in situ profiling of the microbiome is transforming how NASA assesses risk.