Nonreductive biomineralization of uranium by Bacillus subtilis ATCC-6633 under aerobic conditions

Nonreductive biomineralization of uranium is a promising methodology for the removal of uranium contamination as it provides stable products and wide applications. However, the efficiency of mineralization has become a major obstacle for the removal of uranium contamination by this technology, and the mineralizing process still remains largely obscure. To solve this problem in a practical way, we report a fast nonreductive biomineralization process of uranium by Bacillus subtilis ATCC-6633, a widespread bacterium with environmentally-friendly applications. In this system, we demonstrated that the size and crystallization degree of the obtained nonreduced biomineralized products is significantly superior to the results reported in the literature under comparable conditions. Meanwhile, combined with SEM, TEM, and FT-IR, a mineralization process of uranium transfer from the outer surface of the Bacillus subtilis ATCC-6633 to the internal has been clearly observed, which was accompanied by the evolution of amorphous U(VI) to crystalline uramphite. This work uncovers whole-process insights into the nonreductive biomineralization of uranium by Bacillus subtilis ATCC-6633, paving a new way for the rapid and sustained removal of uranium contamination.