School of Chemical & Environmental Engineering, China University of Mining & Technology Beijing, Beijing, 100083, China.
Beijing Station of Agro-Environmental Monitoring, Test and Supervision Center of Agro-Environmental Quality, MOA, Beijing, China.
Environ Pollut. 2021 Dec 15;291:117994. doi: 10.1016/j.envpol.2021.117994. Epub 2021 Aug 19.
Soil around the gold tailing due to the smelting process of wastewater and solid waste can lead to metal (loids) contamination, especially arsenic (As). Soil microorganisms have gradually evolved adaptive mechanisms in the process of long-term adaptation to As contamination. However, comprehensive investigations on As metabolism genes and their host microbial communities in soil profiles with different levels under long-term As contamination are lacking. There are selected three typical soil profiles (0-100 cm) with different metal (loids) contamination levels (L-low, M-moderate and H-high) around tailings in this research. It uses a Metagenomic approach to explore the adaptation mechanisms of arsenic metabolism genes and arsenic metabolism gene host microorganisms in both horizontal and vertical dimensions. The results showed that four categories of As metabolism genes were prevalent in soil profiles at different As contamination, with As reduction genes being the most abundant, followed by As oxidation genes, then respiration genes and methylation genes. The As metabolism genes arsBCR, aioE, arsPH, arrAB increased with the increase of metal (loid) contaminants concentration. Longitudinal arsA, arrA, aioA, arsM and acr3 increased in abundance in deep soil. Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi were the dominant phylum of As metabolism gene host microorganisms. Different concentrations of metal (loid) contamination significantly affected the distribution of host As metabolism genes. Random forest prediction identified As as the most critical driver of As metabolism genes and their host microorganisms. Overall, this study provides a reference for a comprehensive investigation of the detoxification mechanisms of As metabolism microorganisms in soil profiles with different As contamination conditions, and is important for the development of As metabolism gene host microbial strains and engineering applications of microbial technologies to manage As contamination.
由于冶炼过程中的废水和固体废物，尾矿周围的土壤可能导致金属（类金属）污染，特别是砷（As）。土壤微生物在长期适应 As 污染的过程中逐渐进化出了适应机制。然而，对于长期 As 污染下不同水平土壤剖面中砷代谢基因及其宿主微生物群落的综合研究还很缺乏。本研究选取尾矿周围具有不同金属（类金属）污染水平（低污染 L、中污染 M 和高污染 H）的三个典型土壤剖面（0-100 cm）。采用宏基因组学方法，从水平和垂直两个维度探讨了砷代谢基因及其宿主微生物对砷的适应机制。结果表明，砷代谢基因在不同砷污染土壤剖面中均存在四类，其中砷还原基因最为丰富，其次是砷氧化基因，然后是呼吸基因和甲基化基因。砷代谢基因 arsBCR、aioE、arsPH、arrAB 随着金属（类金属）污染物浓度的增加而增加。纵向的 arsA、arrA、aioA、arsM 和 acr3 在深层土壤中丰度增加。Actinobacteria、Proteobacteria、Acidobacteria 和 Chloroflexi 是砷代谢基因宿主微生物的主要门。不同浓度的金属（类金属）污染显著影响宿主砷代谢基因的分布。随机森林预测确定砷是砷代谢基因及其宿主微生物的最关键驱动因素。总的来说，本研究为全面研究不同砷污染条件下土壤剖面中砷代谢微生物的解毒机制提供了参考，对于砷代谢基因宿主微生物菌株的开发和利用微生物技术工程来管理砷污染具有重要意义。
