Effects of veterinary medicines on the functional diversity of the microbial biomass in soils

抗生素通过分散农业中用作肥料的污泥和粪便进入环境。由于它们对细菌的有效性，重要的土壤功能可能会受到影响，元素循环的过程可能会受到干扰。以磺胺嘧啶为研究对象，检测了两种供试土壤中几种氮素循环基因表达的变化，以及对不同氮素转化过程的影响。这种作用具有时间和剂量依赖性。然而，这项效果研究是在实验室条件下单一使用抗生素进行的，使用的是散装土壤。特别是，在现场条件下和反复使用后，没有关于磺胺嘧啶(和二氟沙津)或其他磺胺类药物(分别和氟喹诺酮类)对功能或结构多样性的影响的结果。为了评估抗生素在环境中的风险，现场实验是最重要的，因为在野外和实验室条件下，抗生素的命运可能不同。土壤系统的异质性、植物群落的异质性、粪便的分布以及根际等热点地区土壤细菌的空间聚集决定了土壤中效应的发生。此外，反复使用抗生素可能会改变微生物群落的反应模式。

Antibiotics enter the environment by dispersion of sludge and manure used as fertilizer in agriculture. Due to their effectiveness against bacteria important soil functions could be affected and processes in element cycles might be disturbed. Studying the antibiotic sulfadiazine changes in the gene expressions of several N-cycling genes as well as effects on different N-transformation processes of two test soils were detected. The effects were time and dose dependent. However this effect study was performed with a single application of the antibiotic under laboratory conditions and using bulk soil. Especially no results on effects on functional or structural diversity of sulfadiazine (and difloxazin) or other sulfonamides (and fluroquinolones, respectively) are available under field conditions and after repeated application. To asses the risks of antibiotics in the environment field experiments are most important since the fate of antibiotics might differ under field and laboratory conditions. The heterogeneity of the soil system, plant communities, the manure distribution and the spatial concentration of soil bacteria in hot spots, like the rhizosphere, determine the occurrence of effects in soils. Furthermore repeated application of the antibiotics might change the response pattern of microbial communities.