摘要

以金霉素（CTC），土霉素（OTC）和四环素（TC）为模板抗生素，研究了电动力学处理抗生素污染土壤（EKA）过程中微生物群落的演变。在动力学过程中，土壤微生物总数较少受到影响，而活性抗CTC，抗OTC，抗TC和抗MIX细菌分别被灭活10.48％，31.37％，34.76％和22.08％在7天的治疗期间与没有电场的抗生素污染的土壤（NOE）相比。因此，具有NOE处理的样品显示出比具有EKA处理的样品更高的Shannon指数，表明在电动过程之后微生物群落多样性降低。在EKA和NOE处理样品中发现的主要分类学门类是Proteobacteria，Bacteroidetes，Firmicutes和Actinobacteria。与空白土相比，放线菌，蓝细菌和绿藻的分布大大降低。在变形菌门中，补充抗生素的土壤中Alphaproteobacteria的丰度大大降低（从空白土壤的13.40％到处理后的6.43-10.16％）;而Betaproteobacteria和Deltaproteobacteria则表现出与空白土壤相比丰度增加的不同趋势，并且所有处理的Gammaproteobacteria保持不变（2.36-2.78％）。不同类别的不同趋势表明，由于对抗生素和电场的不同适应性，主要细菌群随治疗而改变。 SulI是一个例外，在用EKA和NOE处理的0-2cm土壤中观察到的包括tetC，tetG，tetW，tetM，intI1和sulII的抗生素抗性基因（ARG）的减少比率分别达到55.17％，3.59％ 99.26％，89.51％，30.40％和27.92％。最后，在抗生素抗性细菌，ARG和分类细菌类别之间进行相关分析。发现在所研究的七种ARG中，sulII是许多不同细菌中最具代表性的。这是EKA之前和之后微生物群落变化的第一份报告，并且目前的结果表明EKA的应用是抑制抗生素抗性微生物和ARGs的有用和有效的方法。

The evolution of microbial communities during the electrokinetic treatment of antibiotic-polluted soil (EKA) was investigated with chlortetracycline (CTC), oxytetracycline (OTC) and tetracycline (TC) as template antibiotics. The total population of soil microorganismswas less affected during the electrokinetic process, while living anti-CTC, anti-OTC, anti-TC and anti-MIX bacteria were inactivated by 10.48%, 31.37%, 34.76%, and 22.08%, respectively, during the 7-day treatment compared with antibiotic-polluted soil without anelectric field (NOE). Accordingly, samples with NOE treatment showed a higher Shannon index than those with EKA treatment, indicating a reduction of the microbial community diversity after electrokinetic processes. The major taxonomic phyla found in the samples of EKA and NOE treatment were Proteobacteria, Bacteroidetes, Firmicutes andActinobacteria. And the distribution of Actinobacteria, Cyanobacteria, and Chloroflexi was greatly decreased compared with blank soil. In the phylum Proteobacteria, the abundance of Alphaproteobacteria was greatly reduced in the soils supplemented with antibiotics (from 13.40% in blank soil to 6.43–10.16% after treatment); while Betaproteobacteria andDeltaproteobacteria showed a different trend with their abundance increased compared to blank soil, and Gammaproteobacteria remained unchanged for all treatments (2.36–2.78%). The varied trends for different classes indicated that the major bacterial groups changed with the treatments due to their different adaptability to the antibiotics as well as to the electric field. SulI being an exception, the reduction ratio of the observed antibiotic resistance genes (ARGs) including tetC, tetG, tetW, tetM, intI1, and sulII in the 0–2 cm soil sampled with EKA versus NOE treatment reached 55.17%, 3.59%, 99.26%, 89.51%, 30.40%, and 27.92%, respectively. Finally, correlation analysis was conducted between antibiotic-resistant bacteria, ARGs and taxonomic bacterial classes. It was found that sulII was the most representative of many different bacteria among the seven ARGs studied. This is the first report on the changes in microbial communities before and after EKA, and the present results demonstrated that the application of EKA is a useful and effective approach to suppressing both antibiotic resistant microorganisms and ARGs.

https://www.sciencedirect.com/science/article/pii/S0147651317308114