Table_1_Microbial community structure in an uranium-rich acid mine drainage site: implication for the biogeochemical release of uranium.XLSX

The generation of acid mine drainage (AMD) characterized by high acidity and elevated levels of toxic metals primarily results from the oxidation and dissolution of sulfide minerals facilitated by microbial catalysis. Although there has been significant research on microbial diversity and community composition in AMD, as well as the relationship between microbes and heavy metals, there remains a gap in understanding the microbial community structure in uranium-enriched AMD sites. In this paper, water samples with varying levels of uranium pollution were collected from an abandoned stone coal mine in Jiangxi Province, China during summer and winter, respectively. Geochemical and high-throughput sequencing analyses were conducted to characterize spatiotemporal variations in bacterial diversity and community composition along pollution groups. The results indicated that uranium was predominantly concentrated in the AMD of new pits with strong acid production capacity, reaching a peak concentration of 9,370 μg/L. This was accompanied by elevated acidity and concentrations of iron and total phosphorus, which were identified as significant drivers shaping the composition of bacterial communities, rather than fluctuations in seasonal conditions. In an extremely polluted environment (pH < 3), bacterial diversity was lowest, with a predominant presence of acidophilic iron-oxidizing bacteria (such as Ferrovum), and a portion of acidophilic heterotrophic bacteria synergistically coexisting. As pollution levels decreased, the microbial community gradually evolved to cohabitation of various pH-neutral heterotrophic species, ultimately reverting back to background level. The pH was the dominant factor determining biogeochemical release of uranium in AMD. Acidophilic and uranium-tolerant bacteria, including Ferrovum, Leptospirillum, Acidiphilium, and Metallibacterium, were identified as playing key roles in this process through mechanisms such as enhancing acid production rate and facilitating organic matter biodegradation.

酸性矿山排水（Acid Mine Drainage, AMD）是以高酸度及升高的有毒金属浓度为典型特征的水体，其生成主要源于微生物催化作用下硫化矿物的氧化与溶解过程。尽管当前针对AMD中的微生物多样性、群落组成，以及微生物与重金属间的关联已开展了大量研究，但针对富铀AMD生境的微生物群落结构认知仍存在空白。
本研究分别于夏季与冬季，从中国江西省某废弃石煤矿山采集了不同铀污染梯度的水样。通过地球化学分析与高通量测序（high-throughput sequencing）技术，解析了不同污染组中细菌多样性与群落组成的时空分布特征。
结果显示，铀主要富集于产酸能力较强的新坑AMD中，峰值浓度达9370 μg/L，同时伴随酸度升高及铁、总磷浓度上升。上述因素被证实为驱动细菌群落组成的关键调控因子，而非季节波动。在pH<3的极端污染环境中，细菌多样性最低，嗜酸铁氧化细菌（Ferrovum）占据优势地位，同时有部分嗜酸异养细菌协同共存。随着污染水平降低，微生物群落逐渐演变为多种pH中性异养物种共存，最终恢复至背景水平。
pH是调控AMD中铀生物地球化学释放的主导因子。研究证实，Ferrovum、Leptospirillum、Acidiphilium及Metallibacterium等嗜酸耐铀细菌，可通过提升产酸速率、促进有机质生物降解等机制在该过程中发挥关键作用。