Microbial purification of perchlorate in a simulated Martian water to ensure its plant cultivation for Martian BLSS

In-situ utilization of Martian water resources is imperative for sustained long-term exploration missions. To address perchlorate contamination that hinders its use in Bioregenerative Life Support Systems (BLSS), this study developed a simulated Martian water (SMW) formula (validated composition, containing 500 mg/L ClO₄⁻ and characteristic ions) and evaluated its microbial purification and subsequent plant cultivation potential. The results showed that screened strains Dechloromonas agitata and Brucella intermedia exhibited ClO₄⁻ removal capabilities in the SMW. Under optimized conditions of inoculum amount (OD₆₀₀ = 0.2), pH 7.5, and extra nutrients (CH₃COONa 1.8 g/L, NH₄Cl 0.25 g/L, NaH₂PO₄ 0.6 g/L), Dechloromonas agitata achieved complete degradation of 500 mg/L ClO₄⁻ within 10 days, while Brucella intermedia accomplished full degradation in 5-fold diluted SMW within 15 days. Cultivation of ClO₄⁻-sensitive plants (wheat, lettuce) using the purified SMW resulted in 95 % seed germination and significantly enhanced morphological indices (leaf length, plant height) and physiological parameters (photosynthetic pigment content, net photosynthetic rate) compared to the untreated control. Critically, no ClO₄⁻ residue was detected in plant tissues cultivated with the purified SMW. These results demonstrate that the developed technology effectively produces water meeting BLSS cultivation requirements, thereby offering a viable pathway for in-situ Martian water utilization.