Abstract:

The substantial production, low storage capacity, wide distribution, regulatory challenges, and low utilization rate of metal tailings in China have raised significant concerns regarding environmental pollution. The study of the mechanisms by which microorganisms adapt to and regulate metal tailings is of great practical significance for bioremediation and is a critical component of efforts to control heavy metal pollution. This study provides an overview of the knowledge regarding the species composition of microbial communities in metal tailings, and presents their adaptation and regulatory mechanisms in response to pH, heavy metals, and nutrient dynamics. Microbial composition analysis revealed that Proteobacteria, Actinobacteria, Chloroflexi, Firmicutes, and Acidobacteria were the dominant bacterial phyla; Ascomycota, Basidiomycota, and Rozellomycota were the dominant fungal phyla; and Thaumarchaeota and Euryarchaeota were the dominant archaeal phyla in the metal tailings. Microorganisms that inhabit metal tailings have been identified as K-strategists. These microorganisms adapt to a highly acidic and metal-rich environment through mechanisms that can either prevent the influx of protons and heavy metal ions into the cells or actively expel them from the intracellular space. Moreover, microorganisms in metal tailings have evolved several adaptive strategies. Some microorganisms can efficiently utilize limited resources to obtain essential nutrients under nutrient-limited conditions. In addition, these microorganisms can actively contribute to improving the tailing environment by regulating pH through proton neutralization and by transforming and precipitating heavy metals to reduce their toxicity. Some microorganisms can accumulate nutrients through carbon and nitrogen fixation, as well as by facilitating the dissolution of inorganic phosphorus. Finally, remediating plants, such as leguminous plants, can improve the tailing environment by secreting secondary metabolites that attract beneficial microorganisms. The study of the microbial remediation of metal tailings requires a comprehensive examination of the dynamic changes in microbial communities during weathering and remediation processes, the use of multi-omics technology to screen microbial remediation agents, and an exploration of the horizontal gene transfer mechanisms of microorganisms, viral diversity in metal tailings, interactions among microorganisms, and interactions between microorganisms and plants. The effective environmental management of metal tailings can be achieved by thoroughly exploring the potential of microorganisms to promote ecological restoration.

Key words: metal tailings, micro-organisms, adaptation, regulation, acid, heavy metals, nutrients

摘要：

当前中国金属尾矿产生量和贮存量大、分布广、监管难度大、综合利用率低，由此而引起的环境污染问题引起了广泛关注。研究金属尾矿微生物对尾矿环境的适应和调控机制对于尾矿的生物修复具有重要的现实意义，是加强重金属污染防控的重要组成部分。综述了金属尾矿微生物群落的物种组成，并从pH、重金属和养分方面阐明其对尾矿环境的适应和调控机制。结果表明，金属尾矿中的优势细菌主要为变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、绿弯菌门（Chloroflexi）、厚壁菌门（Firmicutes）和酸杆菌门（Acidobacteria）；优势真菌主要为子囊菌门（Ascomycota）、担子菌门（Basidiomycota）和罗兹菌门（Rozellomycota）；奇古菌门（Thaumarchaeota）和广古菌门（Euryarchaeota）是其中的优势古菌。金属尾矿微生物属于K型策略微生物，它们通过阻止质子和重金属离子进入细胞和从细胞内部排出质子和重金属离子的方式来适应尾矿极酸性和高含量重金属环境，并在养分限制下利用有限的资源获取营养。微生物还进化出了主动改变尾矿环境的能力，它们通过中和质子以及转化和沉淀重金属的方式提高尾矿环境pH值和降低重金属的毒性，并通过固碳、固氮作用和溶解无机磷来积累养分。此外，豆科植物等修复植物能通过分泌次级代谢产物，吸引有益微生物参与尾矿环境的改善。对于金属尾矿的微生物修复研究，可以从金属尾矿风化和修复期间微生物群落的动态变化、多组学技术联合筛选尾矿修复菌剂、微生物的水平基因转移机制、金属尾矿中病毒多样性、微生物之间和微生物与植物的相互作用等方面深入研究，充分发掘金属尾矿微生物在促进生态修复方面的潜力，为金属尾矿环境治理提供科学的解决方案。

关键词: 金属尾矿, 微生物, 适应, 调控, 酸, 重金属, 养分