Abstract：
Heavy metal pollution can have adverse impacts on microorganisms, plants and even human health. To date, the impact of heavy metals on bacteria in farmland has yielded poor attention, and there is a paucity of knowledge on the impact of land type on bacteria in mining area with heavy metal pollution. Around a metal-contaminated mining area, two soil depths in three types of farmlands were selected to explore the composition and function of bacteria and their correlations with the types and contents of heavy metals. The compositions and functions of bacterial communities at the three different agricultural sites were disparate to a certain extent. Some metabolic functions of bacterial community in the paddy field were up-regulated compared with those at other site. These results observed around mining area were different from those previously reported in conventional farmlands. In addition, bacterial community composition in the top soils was relatively complex, while in the deep soils it became more unitary and extracellular functional genes got enriched. Meanwhile, heavy metal pollution may stimulate the enrichment of certain bacteria to protect plants from damage. This finding may aid in understanding the indirect effect of metal contamination on plants and thus putting forward feasible strategies for the remediation of metal-contaminated sites. MAIN FINDINGS OF THE WORK: This was the first study to comprehensively explore the influence of heavy metal pollution on the soil bacterial communities and metabolic potentials in different agricultural land types and soil depths around a mining area.
摘要：
重金属污染会对微生物产生不利影响，植物甚至人类健康。迄今为止,重金属对农田细菌的影响引起了人们的关注，关于土地类型对重金属污染矿区细菌的影响缺乏了解。在一个金属污染的矿区周围，选择三种类型农田的两种土壤深度，探讨细菌的组成和功能及其与重金属类型和含量的相关性。三个不同农业地点的细菌群落的组成和功能在一定程度上不同。与其他部位相比，稻田细菌群落的某些代谢功能上调。在矿区周围观察到的这些结果与以前在常规农田中报告的结果不同。此外,表层土壤中的细菌群落组成相对复杂，而在深层土壤中，它变得更加单一，细胞外功能基因得到了丰富。同时,重金属污染可能刺激某些细菌的富集，以保护植物免受损害。这一发现可能有助于理解金属污染对植物的间接影响，从而提出修复金属污染场地的可行策略。这项工作的主要发现：这是第一项全面探索重金属污染对矿区不同农业用地类型和土壤深度中土壤细菌群落和代谢潜力的影响的研究。
