摘要

重金属污染土壤是世界性问题，特别是在中国。土壤细菌群落结构，抗生素抗性基因与土壤中重金属污染之间的相互关系尚不清楚。在这里，有七个重金属污染的农业区（G1-G7）以不同的距离（741至2556米）向工厂采样。使用变性梯度凝胶电泳（DGGE）和香农指数来分析细菌群落多样性。实时荧光定量PCR用于检测ARGs sul1，sul2，tetA，tetM，tetW，一个移动遗传元件（MGE）的相对丰度。结果表明，所有样品均受镉（Cd）污染，部分受铅（Pb），汞（Hg），砷（As），铜（Cu）和锌（Zn）污染。 DGGE显示在G7中发现的最重的细菌物种具有最轻的重金属污染。主成分分析和聚类分析的结果都表明，G7不能与其他样本进行分类。 sul1的相对丰度与Cu，Zn浓度相关。基因sul2与总磷呈正相关，tetM与有机物有关。总基因丰度和相对丰度inti1都与有机物相关。冗余分析表明，Zn和sul2与细菌群落结构显着相关。总之，我们的结果表明土壤重金属浓度，细菌群落组成和一些全球传播的ARG丰度之间存在复杂的联系。

Soil contamination with heavy metals is a worldwide problem especially in China. The interrelation of soil bacterial community structure, antibiotic resistance genes, and heavy metal contamination in soil is still unclear. Here, seven agricultural areas (G1–G7) with heavy metal contamination were sampled with different distances (741 to 2556 m) to the factory. Denaturing gradient gel electrophoresis (DGGE) and Shannon index were used to analyze bacterial community diversity. Real-time fluorescence quantitative PCR was used to detect the relative abundance of ARGs sul1, sul2, tetA, tetM, tetW, one mobile genetic elements (MGE)inti1. Results showed that all samples were polluted by Cadmium (Cd), and some of them were polluted by lead (Pb), mercury (Hg), arsenic (As), copper (Cu), and zinc (Zn). DGGE showed that the most abundant bacterial species were found in G7 with the lightest heavy metal contamination. The results of the principal component analysis and clustering analysis both showed that G7 could not be classified with other samples. The relative abundance of sul1 was correlated with Cu, Zn concentration. Gene sul2 are positively related with total phosphorus, and tetM was associated with organic matter. Total gene abundances and relative abundance ofinti1 both correlated with organic matter. Redundancy analysis showed that Zn and sul2 were significantly related with bacterial community structure. Together, our results indicate a complex linkage between soil heavy metal concentration, bacterial community composition, and some global disseminated ARG abundance.

https://link.springer.com/article/10.1007/s11356-018-1251-8