Single-cell Raman spectroscopy and synthetic microbiology power microbial-driven extraterrestrial domestic wastewater treatment

The realization of long-term manned space exploration and extraterrestrial habitation hinges on microbial-based extraterrestrial domestic wastewater (EDW) treatment technology to achieve sustainedly closed-loop water recycling. This perspective recaps the challenges and potential of integrating microbial technology as a sustainable and low-energy alternative for treating EDW compared to physicochemical water recovery systems. Of note, traditional microbial technologies are not directly transferable due to EDW’s unique constraints, including high ammonium, low C/N ratio, and multiple stresses. We proposed how synthetic microbiology integrated with single-cell Raman spectroscopy (SCRS) offers a promising approach to engineer stable, efficient microbiomes tailored for EDW treatment. SCRS coupled with stable isotope probing can enable precise identification and isolation of stress-tolerant functional microorganisms at the single-cell level, bypassing lengthy enrichment methods. SCRS can also serve as a real-time monitoring tool for system optimization and early warning, enabling resilient, intelligently monitored biological systems for extraterrestrial water recycling.