摘要
      由于抗生素耐药性基因（ARGs）的刺激增殖和传播，土壤中的抗生素污染对人类健康构成了越来越大的威胁。纳米零价铁（NZVI）是一种很有前途的抗生素修复材料，但NZVI如何影响ARGs的多样性、丰度和水平基因转移潜力尚不清楚。本文研究了不同浓度的NZVI对四环素类药物（TC）和相关ARGs的生物和非生物影响。结果表明，NZVI可以有效加速TC的降解，在20天内从51.38%（不含NZVI）增加到57.96%−71.66%（1-10 g NZVI/kg）。生物降解占总TC去除量的66.10%-76.30%。NZVI诱导的TCs生物降解可能是由于TCs对细胞的毒性减轻以及微生物生物量和酶活性增加。此外，与TC相关的ARGs随着intI1和ISCR1水平基因转移潜力的降低而减弱，但对非TC相关的ARGs观察到相反的作用，尤其是在过量暴露于NZVI期间。本研究说明了NZVI修复抗生素污染土壤的可能性，同时降低ARGs的潜在风险。
Abstract
Antibiotics pollution in soil poses increasing threats to human health due to stimulated proliferation and transmission of antibiotic resistance genes (ARGs). Nanoscale zero-valent iron (NZVI) is a promising material for the remediation of antibiotics, but how NZVI affects the diversity, abundance, and horizontal gene transfer potentials of ARGs remains unclear. Herein, the biotic and abiotic effects of NZVI at different concentrations on tetracyclines (TCs) and the associated ARGs were investigated. Results showed NZVI could effectively accelerate the degradation of TCs, which increased from 51.38% (without NZVI) to 57.96%− 71.66% (1–10 g NZVI/kg) in 20 days. Biotic degradation contributed to 66.10%− 76.30% of the total TCs removal. NZVI induced TCs biodegradation was probably due to alleviated toxicity of TCs on cells and increased microbial biomass and enzyme activities. Additionally, TCs-related ARGs were attenuated with decreased horizontal gene transfer potentials of intI1 and ISCR1, but opposite effects were observed for non TC-related ARGs, especially during excess exposure to NZVI. This study illustrated the possibility of remediating of antibiotic contaminated soil by NZVI and meanwhile reducing the potential risks of ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S0304389423001498