Key drivers and feedback of soil-water microbial communities and resistance gene in a decommissioned...

Microorganisms are pioneer responders to environmental change and play an irreplaceable role in the biogeochemical cycle of uranium, and the feedback of microorganisms to heavy metals basically affects the function and stability of ecosystems. We investigated the microbial diversity inhabiting uranium and associated heavy metals from a decommissioned uranium (U) mining area in southwest China. The results showed that the soil and mine water contained uranium and associated metals, among which the content of uranium was as high as 500 mg/kg and 40 mg/L, respectively. Heavy metal pollution restricted the proliferation and metabolism of microorganisms. Microbial diversity profiling identified Pseudomonadota as the predominant phylum in the areas. Redundancy analysis (RDA) revealed that arsenic, lithium (Li), and moisture were key drivers in microbial community assembly, with Li being specifically identified as a driver of metal-resistance genes (MRGs) in soil. In addition, we identified potential uranium resistance genes. Li has been identified for the first time as the primary driver of microbial community structure and MRGs under uranium and associated metal stresses. This study revealed the response characteristics of microorganisms to polymetallic pollution while proposing new insights for the bioremediation of uranium and associated heavy metals.