PDF(Pubmed)
Abstract：
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.
摘要：
以高酸度和有毒金属含量升高为特征的酸性矿山排水（AMD）的产生主要是由于微生物催化促进了硫化物矿物的氧化和溶解。尽管在AMD中微生物多样性和群落组成方面已有大量的研究,以及微生物和重金属之间的关系，在了解富铀AMD站点的微生物群落结构方面仍存在差距。在本文中,从江西省一个废弃的石煤矿收集了不同程度的铀污染水样，中国在夏季和冬季，分别。进行了地球化学和高通量测序分析，以表征污染组细菌多样性和群落组成的时空变化。结果表明，铀主要集中在具有强酸生产能力的新矿坑的AMD中，达到9,370μg/L的峰浓度这伴随着酸度和铁和总磷浓度的升高，它们被确定为影响细菌群落组成的重要驱动因素，而不是季节性条件的波动。在极端污染的环境中（pH<3），细菌多样性最低，主要存在嗜酸性铁氧化细菌（如Ferrovum），和一部分嗜酸异养细菌协同共存。随着污染水平的下降，微生物群落逐渐演变为各种pH中性异养物种的同居，最终回到背景水平。pH是决定AMD中铀的生物地球化学释放的主要因素。嗜酸和耐铀细菌，包括Ferrovum,钩端螺旋体,嗜酸杆菌,和金属细菌，被确定为通过提高产酸率和促进有机物生物降解等机制在此过程中发挥关键作用。
