摘要
      尽管在农田中利用生物固体被广泛认为是提高资源再利用的有效途径，但抗生素抗性基因（ARGs）的存在严重限制了生物固体重返农田。进行了一项为期12年的长期实验，研究了不同生物固体施用率（0至36 t ha−1 yr−1）对土壤中ARGs形成的影响。施用生物固体显著增加了土壤中ARGs的丰度，但MBS处理除外（施用9 t ha−1 yr−1种生物固体）。土壤中ARGs的丰度并没有随着施用生物固体的剂量而线性增加，但它们之间存在显著的正相关（P<0.05）。共检测到173种亚型，其中以移动遗传元件（MGEs）、氨基糖苷类和多药耐药基因为主。除MBS处理外，在长期连续施用生物固体后，大多数检测到的ARGs在改良土壤中富集。具体而言，tetPA、sul1、mefA和IS6100在所有改良土壤中都高度富集。此外，施用生物固体增加了土壤养分和重金属，并改变了土壤微生物群落，所有这些都影响了ARGs的形成。但MGE可能是形成ARGs剖面的一个比土壤性质更大的因素。总体而言，控制生物固体的施用速率是减少ARGs在土壤中积累和水平转移的关键。
Abstract
Although the utilization of biosolids in agricultural lands is widely considered as an effective way to improve resource reuse, the presence of antibiotic resistance genes (ARGs) severely restricts biosolids returning to fields. A 12-year long-term experiment with different biosolids application rates (from 0 to 36 t ha−1 yr−1) was conducted to study the effect of biosolids application on shaping ARGs in soil. Biosolids application significantly increased ARGs abundance in the soil, except for MBS treatment (9 t ha−1 yr−1 biosolids application). The abundance of ARGs in soil did not increase linearly with the dose of biosolids applied, but they were significantly (P < 0.05) positively correlated. A total of 173 subtypes were detected, among them mobile genetic elements (MGEs), aminoglycoside, and multidrug resistance genes were the most dominant types. Except for MBS treatment, most of the ARGs detected were enriched in amended soils after long-term continuous biosolids application. Specifically, tetPA, sul1, mefA, and IS6100 were highly enriched in all amended soils. In addition, biosolids application increased soil nutrients and heavy metals, and changed the soil microbial community, all of which affected ARGs formation. But MGEs may be a greater factor for shaping ARGs profiles than soil properties. Overall, controlling the rate of biosolid application is the key to reducing the accumulation and horizontal transfer of ARGs in soils.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122002433