Microgravity's grip: Transforming plant-microbe interactions for space sustainability

The development of bioregenerative life support systems is essential for sustainable space exploration, reducing Earth-reliant resupply and ensuring human survival in extreme extraterrestrial conditions. A key research focus is the microgravity assessment of Biological Life Support Systems (BLSS), with a focus on gas exchange, critical for habitability. This study introduces a two-loop miniature closed artificial ecosystem (BMCAE) to analyze gas balance within plant-microbe systems under simulated microgravity. The BMCAE, featuring wheat for photosynthesis and microbes for waste management and nutrient cycling, is designed to accommodate spatial constraints while maintaining system stability. A 3D clinostat simulates microgravity to evaluate the BMCAE's capacity to support plant growth and microbial activity. Gas chromatography and next-generation sequencing assess the effects of simulated microgravity on plant and microbial dynamics. Results show that wheat growth responds positively to light intensity but is less robust under simulated microgravity, suggesting a negative impact on growth. Microbial community composition and diversity are significantly altered by simulated microgravity, particularly at lower temperatures, with an enrichment of Firmicutes and Bacillus, indicating microbial adaptation to microgravity. This research provides a theoretical and methodological basis for BMCAE application in space, aiding in the development of miniature ecosystems for BLSS, crucial for sustainable human life support in space.