Microbial community structure and succession of airborne microbes in closed artificial ecosystem

Microbes play a significant role in achieving substance circulation and regeneration in closed artificial ecosystems (CAES) such as bioregenerative life support system (BLSS), greenhouses, and aquaria. In order to understand the pattern of microbial development inside such closed systems, a ground-based closed comprehensive BLSS experimental system named “Lunar Palace 1 (LP1)” was established and a 105-day manned BLSS experiment was carried out in LP1 by our team. During this closed experiment, airborne microbes in the closed cabins of LP1 were sampled and the development and succession law of microorganisms were analyzed using both plate cultivation and molecular biology methods. The results indicated that the dominant bacteria in the air of LP1 were Cupriavidus, Afipia, Delftia, Cyanobacteria and Enterococcus and the dominant fungi were Penicillium, Alternaria, Aspergillus and Cochliobolus, which included not only ubiquitous environmental microorganisms but also opportunistic pathogens. And the succession of dominant microbes' composition also provided an important experience for solving the problem of microbial contamination in CAES and set a solid foundation for establishing more targeted microbial prevention and control measures in long-term multi-crew closed BLSS experiments in the future.