Study on the spatial distribution of ureolytic microorganisms in farmland soil around tailings with different heavy metal pollution
Study on the spatial distribution of ureolytic microorganisms in farmland soil around tailings with different heavy metal pollution
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DOI：
10.1016/j.scitotenv.2021.144946
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发表时间：
2021-02-19
影响因子：
9.8
通讯作者：
Yu, Caihong
中科院分区：
文献类型：
--
作者：
Hu, Xuesong;Liu, Xiaoxia;Yu, Caihong
溶脲微生物是一类能够分泌脲酶并分解尿素的微生物，在基于微生物诱导碳酸盐沉淀的土壤重金属修复中具有巨大的应用潜力。然而，对重金属污染土壤中尿素分解微生物群落的水平和垂直分布规律的研究还很少。本研究首次采用宏基因组技术，从重金属污染（Low-L、Middle-M、High-H）和土壤深度（0-20 cm、20-40 cm、40-60 cm、60-80 cm、80-100 cm）两个维度对尾矿库周边农田土壤脲酶基因进行了研究。结果表明，重金属浓度对土壤中尿素分解微生物的影响确实显著，但在同一重金属污染水平下，尿素分解微生物随土壤深度的变化在垂直方向上存在差异。除表土外，H点的尿素分解微生物多样性最高。在相同的重金属污染水平下，深层土壤的尿素分解微生物多样性较低。变形菌门、放线菌门和古菌门是3个地点尿素分解微生物的优势类群，占总数的80%以上。但三门植物对重金属浓度的响应不同，分别为增加、减少和基本不变。除此之外，土壤有机质和pH值等环境因子对尿素分解菌的影响也各不相同，其中变形菌与尿素分解菌呈正相关，放线菌与尿素分解菌呈负相关。另一现象是放线菌和疣微菌是L组的生物标志物，这可以显著解释与其他两个地点的差异。这些结果为进一步研究尿素分解微生物系统对重金属污染的响应机制和修复提供了有价值的信息。(c)2021年由Elsevier B. V.出版
Ureolytic microorganisms, a kind of microorganism which can secrete urease and decompose urea, have great potential in remediation of soil heavy metals based on microbial induced carbonate precipitation. However, the horizontal and vertical distribution of ureolytic microbial community in heavy metals contaminated soils is poorly understood. In this study, urease genes in agricultural soils surrounding tailings were first investigated using metagenomic in two dimensions: heavy metal pollution (Low-L, Middle-M, High-H) and soil depth (0-20 cm, 20-40 cm, 40-60 cm, 60-80 cm, 80-100 cm). Results showed that the effect of heavy metal concentration on ureolytic microorganisms was indeed significant, while the changes of ureolytic microorganisms with increasing soil depth varied in the vertical direction at the same level of heavy metal contamination. H site had the highest diversity of ureolytic microorganisms except for the topsoil. And at the same heavy metal contamination level, the ureolytic microbial diversity was lower in deeper soils. Proteobacteria, Actinobacteria and Thaumarchaeota (Archaea) were the dominant phyla of ureolytic microorganisms in all three sites, accounting for more than 80% of the total. However, the respond to the heavy metal concentrations of three phyla were different, which were increasing, decreasing and essentially unchanged, respectively. Besides, other environmental factors such as SOM and pH had different effects on ureolytic microorganisms, with Proteobacteria being positively correlated and Actinobacteria being the opposite. Another phenomenon was that Actinobacteria and Verrucomicrobia were biomarkers of group L, which could significantly explain the difference with the other two sites. These results provided valuable information for further research on the response mechanism and remediation of heavy metal pollution by ureolytic microbial system. (c) 2021 Published by Elsevier B.V.