Computational Systems Biology Lab

NASA cleanrooms, which are critical for assembling space mission components, are maintained under stringent decontamination protocols to minimize biological contamination. These environments are characterized by nutrient-poor and oligotrophic conditions, leading to low microbial loads. Despite extensive cleaning, oligotrophs capable of surviving in such conditions continue to persist, often remaining undetected due to their low abundance, resistance to environmental stresses, and difficulties in biomolecule extraction. Even with shotgun metagenome sequencing technologies, these microbes may go undetected or be underrepresented due to their robust cell walls and the absence of reference genomes in publicly available databases. Over a 6-month study of Mars 2020 mission cleanrooms, 182 bacterial strains belonging to 19 families were identified using a whole-genome sequencing (WGS) approach. Among these, 14 novel Gram-positive species were discovered, including eight spore formers. Though the novel species comprised only 0.001% of the sequencing data, their successful cultivation allowed for functional characterization. Through WGS data mining, genomic traits associated with resilience in extreme conditions were revealed. These species were found to be involved in nitrogen cycling, carbohydrate metabolism, and radiation resistance, traits essential for survival in extreme environments. Furthermore, 12 biosynthetic gene clusters were identified, including those linked to ectoine and 𝜖 -poly-L-lysine production, suggesting potential biotechnological applications. These findings highlight the hidden microbial diversity within cleanrooms and emphasize the necessity of advanced detection strategies. A better understanding of these microbes will provide insights into extremophiles with applications in biotechnology, medical research, and life support systems for future space exploration missions.