Identification and Taxonomic Analysis of Novel Bacterial Species of the International Space Station

Ensuring that space habitats such as the International Space Station (ISS) are free of harmful microbial contamination is important for the safety of current and future human space exploration. Consistently building databases of space-relevant microorganisms allows for meaningful metagenomic analysis of space habitats and source tracking. The 16SrRNA gene is a highly conserved ribosomal gene used to analyze the taxonomy of bacterial species. In this study, 16S sequences were retrieved from the whole genomes of potential novel bacterial species from the genera Paenibacillus, Leifsonia, Arthrobacter and Sporosarcina collected from the ISS as part of the Microbial Tracking Project. The 16Ssequences were aligned to create phylogenetic trees with related species in the same genus. Based on genetic data, these species are novel, but this must be confirmed with chemotaxonomic analysis. These novel species can be assessed for potential pathogenicity or beneficial space applications such as aiding in plant growth.