Dissipation and sequestration of the veterinary antibiotic sulfadiazine and its metabolites under field conditions.
Dissipation and sequestration of the veterinary antibiotic sulfadiazine and its metabolites under field conditions.
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DOI：
10.1021/es200326t
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发表时间：
2011-05
影响因子：
11.4
通讯作者：
Ingrid Rosendahl;J. Siemens;J. Groeneweg;Elisabeth Linzbach;V. Laabs;C. Herrmann;H. Vereecken;W. Amelung
中科院分区：
文献类型：
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作者：
Ingrid Rosendahl;J. Siemens;J. Groeneweg;Elisabeth Linzbach;V. Laabs;C. Herrmann;H. Vereecken;W. Amelung
引入环境中的兽用抗生素可能会改变土壤微生物群落的组成和功能，并促进抗生素耐药性的传播。实际风险取决于抗生素的持久性和（生物）可及性，这可能在实验室和现场条件下有所不同。我们研究了磺胺嘧啶（SDZ）及其主要代谢产物在土壤中的田间条件下的耗散和封存，以及它是如何受到温度，土壤水分，植物根系，土壤团聚体相比，控制实验室实验。顺序提取占容易提取（CaCl水可提取）和螯合（微波可提取，残留）SDZ馏分。从这两个馏分的耗散在很大程度上是温度依赖性，可以很好地预测在不同温度下记录的实验室数据。土壤水分似乎还控制螯合，在干燥的土壤中加速。螯合，如增加表观分配系数和降低速率的动力学释放到氯化钙，支配抗生素在土壤中的长期命运。此外，我们观察到的抗生素浓度在土壤团聚体和根附近的空间梯度。前者是短暂的和平衡，由于聚集重组，而消散的容易提取的馏分加速根附近的整个生长期。植物对残留SDZ浓度的影响很小（如果有的话）。
Veterinary antibiotics introduced into the environment may change the composition and functioning of soil microbial communities and promote the spreading of antibiotic resistance. Actual risks depend on the antibiotic's persistence and (bio)accessibility, which may differ between laboratory and field conditions. We examined the dissipation and sequestration of sulfadiazine (SDZ) and its main metabolites in soil under field conditions and how it was influenced by temperature, soil moisture, plant roots, and soil aggregation compared to controlled laboratory experiments. A sequential extraction accounted for easily extractable (CaCl₂-extractable) and sequestered (microwave-extractable, residual) SDZ fractions. Dissipation from both fractions was largely temperature-dependent and could be well predicted from laboratory data recorded at different temperatures. Soil moisture additionally seemed to control sequestration, being accelerated in dry soil. Sequestration, as indicated by increasing apparent distribution coefficients and decreasing rates of kinetic release into CaCl₂, governed the antibiotic's long-term fate in soil. Besides, we observed spatial gradients of antibiotic concentrations across soil aggregates and in the vicinity of roots. The former were short-lived and equilibrated due to aggregate reorganization, while dissipation of the easily extractable fraction was accelerated near roots throughout the growth period. There was little if any impact of the plants on residual SDZ concentrations.