Microbiomes of air dust collected during the ground-based closed bioregenerative life support experiment "Lunar Palace 365"

An early microbial landscape: inspiring endeavor from the China Space Station Habitation Area Microbiome Program (CHAMP)

China's progressing space program, as evidenced by the formal operation of the China Space Station (CSS), has provided great opportunities for various space missions. Since microbes can present potential risks to human health and the normal operation of spacecraft, the study on space-microorganisms in the CSS is always a matter of urgency. In addition, the knowledge on the interactions between microorganisms, astronauts, and spacecraft equipment will shed light on our understanding of life activities in space and a closed environment. Here, we present the first comprehensive report on the microbial communities aboard the CSS based on the results of the first two survey missions of the CSS Habitation Area Microbiome Program (CHAMP). By combining metagenomic and cultivation methods, we have discovered that, in the early stage of the CSS, microbial communities are dominated by human-associated microbes, with strikingly large differences in both composition and functional diversity compared to those found on the International Space Station (ISS). While the samples from two missions of CHAMP possessed substantial differences in microbial composition, no significant difference in functional diversity was found, although signs of accumulating antibiotic resistance were evident. Meanwhile, strong bacteria co-occurrence was noted within the station's microbiota. At the strain level, environmental isolates from the CSS exhibited numerous genomic mutations compared to those from the Assembly, Integration, and Test (AIT) center, potentially linked to the adaptation to the unique conditions of space. Besides, the intraspecies variation within four high-abundance species suggests possible propagation and residency effects between sampling sites. In summary, this study offers critical insights that not only advance our understanding of space microbiology but also lay the groundwork for effective microbial management in future long-term human space missions.

Space biological and human survival: Investigations into plants, animals, microorganisms and their components and bioregenerative life support systems

Space life science has been a frontier discipline in the life sciences, aiming to study the life phenomena of earth organisms and their activity patterns under the special environment of space. This review summarizes studies in various key topics in space life science, namely, how microbiome changes in humans and plants, the development of space agriculture and the use of animal, plant and cell models to study the effect of space environments on physiology. We highlight the new possibilities of using high-quality protein crystals uniquely available when grown under space conditions to aid drug development on earth, and the state-of-the-art Bioregenerative Life Support Systems (BLSS) to achieve long term human survival in space.

Microbiome in a ground-based analog cabin of China Space Station during a 50-day human occupation

Dead-corner areas in space station that untouched by the clean-up campaign often experience microorganisms outbreaks, but the microbiome of these areas has never been studied. In this study, the microbiome in a ground-based analog ``Tianhe'' core module of China Space Station was first investigated during a 50-day three-crew occupation. Dead-corner areas were receiving attention by adopting a new sampling method. Results indicate that the astronauts occupation did not affect the dominant bacteria community, but affected a small proportion. Due to the frequent activity of astronauts in the work and sleep areas, the biomarkers in these two areas are common human skin surface and gut microorganisms, respectively. For areas that astronaut rarely visits, the biomarkers in which are common environmental microbial groups. Fluorescence counting showed that 70.12-84.78% of bacteria were alive, with a quantity of 104-105 cells/100 cm2. With the occupation time extension, the number of microorganisms increased. At the same sampling time, there was no significant bioburden difference in various locations. The cultivable bioburden ranged from 101 to 104 colony forming unit (CFU)/100 cm2, which are the following eight genera Penicillium, Microsphaeropsis, Stachybotrys, Humicola, Cladosporium, Bacillus, Planomicrobium, and Acinetobacter. Chryseomicrobium genus may be a key focus for future microbial prevention and control work.

Characteristics of bacterial community and ARG profiles in the surface and air environments in a spacecraft assembly cleanroom

Understanding the microbial communities and antibiotic resistance genes (ARGs) in spacecraft assembly cleanrooms is crucial for spacecraft microbial control and astronaut safety. However, there have been few reports of ARG profiles and their relationship with microbiomes in such environments. In the present study, we assessed the bacterial community and ARGs in the air dust and surface environments of a typical spacecraft assembly cleanroom. Our results show a significant difference in bacterial composition between surfaces and air dust, as they belong to two distinct ecostates. Bacillus and Acinetobacter were significantly enriched in the air samples. Bacterial community network analysis revealed lower topological parameters and robustness of bacterial networks in the air samples. We also observed different distribution patterns of some typical ARGs between surface and air dust samples. Notably, the ermB gene exhibited a relatively high copy number and was enriched in the surface environment, compared to that in the air. Overall, our study provides insight into the complex microbial community and the distribution and transfer of ARGs in spacecraft assembly cleanrooms, and offers important input for developing control strategies against ARGs.