New insights into uranium biomineralization mediated by Pseudomonas sp. WG2-6 in the presence of organic phosphorus: promoting effect of extracellular polymeric substance and formation of U-P nanominerals

Microbial biomineralization significantly affects the uranium (U) behavior in the environment. However, the mechanism of microbial biomineralization of U is still not fully understood. In this study, a dominant bacterium (Pseudomonas sp. WG2-6) was isolated from U tail mining area. Abiotic precipitation tests demonstrated that U biomineralization was entirely attributed to the mediation of Pseudomonas sp. WG2-6 when the concentration ratio of exogenous β-glycerophosphate (SGP) to U was 10:1. Pseudomonas sp. WG2-6 exhibited strong immobilization ability towards U (97.59 %) according to batch experiments, and acylamide, carbonyls, and phosphate groups were the main functional groups that interacted with U. Besides, U mainly existed in the form of amorphous U-P complexes after biomineralization by Pseudomonas WG2-6, which could be converted into crystalline nano-minerals H