Characterization of the International Space Station (ISS) microbiome has been enabled by culture-based sampling followed by Earth-based analysis. As human exploration pushes beyond low-Earth orbit, microbial-related crew health, planetary protection, and space research questions require in situ capabilities. Steps toward reducing Earth-dependence for complex sample analysis began in 2016 with the amplification of DNA within the miniPCR thermal cycler and DNA sequencing with the MinION sequencer onboard the ISS; for both, samples were prepared on Earth.

In 2017, these platforms synergistically enabled the in situ identification of unknown bacteria collected and cultured from ISS surfaces, thereby shifting the paradigm that microbial cultures had to be returned to Earth. The following year, a culture-independent, swab-to- sequencer method further advanced spaceflight microbiology, demonstrating that culturing could be excluded and providing enhanced insight into the bacterial profile of ISS surfaces. Following the success of these investigations, these methods have been expanded and utilized for routine microbial monitoring of both ISS surfaces and water. Additionally, capabilities have been expanded for whole genome and shotgun metagenomic analyses. This seminar will focus on the efforts toward advancing modern microbiome profiling onboard the ISS, the data collected to date, and future efforts to expand sample type and nanopore sequencing applications.

Dr. Sarah Wallace serves as a technical lead in the Microbiology Laboratory at the NASA Johnson Space Center, which is responsible for mitigating infectious disease risk during human spaceflight. Her responsibilities include the assessment of microbial risk based on vehicle and mission architectures as well as crewmember, food, and environmental monitoring. These assessments are used to develop requirements for NASA and commercial spaceflight vehicles, including the International Space Station. In addition to her operational support of human spaceflight, Dr. Wallace leads new technology initiatives for her discipline with the goal of reducing Earth-dependence for complex sample analysis. She has served as PI for numerous spaceflight investigations, including those to increase off-planet molecular biology capabilities.