摘要

       土壤重金属污染是一个世界性问题，特别是在我国。土壤细菌群落结构、抗生素抗性基因与土壤重金属污染的关系尚不清楚。在这里，对7个重金属污染的农业区（G1-G7）进行了不同距离（741-2556m）的采样。采用变性梯度凝胶电泳（DGGE）和Shannon指数分析细菌群落多样性。采用实时荧光定量PCR方法检测ARGs-sul1、sul2、tetA、tetM、tetW、1个流动基因（MGE）inti1的相对丰度。结果表明，所有样品均受到镉（Cd）的污染，部分样品受到铅（Pb）、汞（Hg）、砷（As）、铜（Cu）、锌（Zn）的污染。DGGE结果表明，G7中细菌种类最丰富，重金属污染最轻。主成分分析和聚类分析结果均表明，G7不能与其它样本进行分类。sul1的相对丰度与Cu、Zn浓度相关。sul2基因与总磷呈正相关，tetM基因与有机质呈正相关。inti1基因总丰度和相对丰度均与有机质有关。冗余分析表明，锌和sul2与细菌群落结构有显著相关性。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分布的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 of inti1 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%2Fs11356-018-1251-8