UC San Diego

Abstract: Earth is the cradle of mankind, but it is impossible for human beings to live in the cradle forever. Sending soil microbial spores through space to foreign planets will be a likely initial process in planet colonization. Periods of hyper-gravity are likely to be a challenge for the candidate microorganisms during their interstellar transportation, raising questions about their survival rates and community-level responses. To address these questions, the impacts of hyper-gravity on soil microbial community composition and activity were tested by applying 1×g or 2500×g centrifugal force to soil for 6 days. The results indicated an increased diversity and absolute abundance of soil total bacterial community and a relatively stable active bacterial community under hyper-gravity condition. Besides, hyper-gravity had no observable effect on the relative abundance of soil microorganisms. These results suggest that soil microorganisms could survive during short periods of hyper-gravity. Our findings represent the first step towards a better understanding of the potential for survival of soil microbiomes during space travel and provide a basis for further interstellar soil research.