Developing microbial communities capable of supporting plants in regolith analogs is essential for in-situ resource utilization and life-support systems. We investigated how Mizuna mustard (Brassica r..
Developing microbial communities capable of supporting plants in regolith analogs is essential for in-situ resource utilization and life-support systems. We investigated how Mizuna mustard (Brassica rapa var. japonica) cultivation and manure amendment restructure microbiomes in a lunar regolith simulant (LHS-1). Four treatments: Unplanted manure-amended regolith (LRM), planted manure-amended regolith (LRMP), planted unamended regolith (LRP), and soil controls, were compared using 16S rRNA amplicon sequencing. Alpha diversity increased from unplanted substrates to rhizosphere samples, and beta diversity showed strong compositional separation (PERMANOVA R² = 0.82, p = 0.01). LRMP rhizospheres shifted from Firmicutes dominance toward soil-like communities enriched in Proteobacteria, Actinobacteria, and Bacteroidetes. No DNA was recovered from unamended LRP rhizospheres, consistent with carbon limitation. Results indicate that organic amendment and plant roots jointly foster soil-like microbial structure in regolith simulants, advancing strategies for establishing productive, self-sustaining microbial ecosystems under future lunar surface agricultural operations.
