Targeted domestication of Enterobacter-dominated consortia for enhanced uranium immobilization via phosphate-mediated...

Indigenous microbiota adapted to uranium-contaminated environments often exhibit strong uranium resistance and environmental adaptability, making them promising candidates for bioremediation. In this study, a functional consortium (WE) was established through long-term acclimation and was dominated by Enterobacter (97.52%). Genomic analysis of the dominant strain, Enterobacter sp. SA187, revealed diverse and active metabolic potentials, providing a genetic basis for its environmental adaptability and competitive advantage. The WE consortium showed a maximum tolerance concentration (MTC) of 50 mg·L^-1and a minimum inhibitory concentration (MIC) of 5 mg·L^-1 for U(Ⅵ). Under optimized conditions (6% inoculum, pH 6.00 ± 0.01, 30℃), it achieved 98.51% removal of U(Ⅵ) at an initial concentration of 10 mg·L^-1. Mechanistic analyses showed that U(Ⅵ) removal occurred mainly through synergistic biosorption and biomineralization. Uranium was associated with cell surface functional groups, including carboxyl, phosphoryl, and amino groups, and was also immobilized in extracellular products. Stable uranium phosphate minerals, predominantly Na((UO₂)(PO₄))·3 H₂O and (UO₂)(HPO₄)·4 H₂O, were identified as the main end-products, confirming phosphate-mediated biomineralization as a key removal pathway. These findings highlight the important role of medium-driven microbial acclimation in enhancing consortium function and provide a practical strategy for the bioremediation of uranium-contaminated water.