University of Alcalá, Alcalá de Henares, Madrid, Spain; Helmholtz Zentrum München, Múnich, Germany.
IMDEA-WATER Parque Tecnológico de Alcalá, Madrid, Spain.
Bioelectrochemistry. 2019 Aug;128:283-290. doi: 10.1016/j.bioelechem.2019.04.008. Epub 2019 Apr 17.
Livestock manures are potential sources of antibiotics in the environment. Sulfamethazine (SMZ), frequently used in veterinary medicine, can enter the environment by using manure as soil fertilizer due to its incomplete absorption in the animal gut and its unmetabolized excretion. The objective of this study was to evaluate the mineralization of C-labelled SMZ in manure under a new redox scenario provided by microbial electrochemical reactors, termed microbial electroremediating cells (MERC). These devices aim to overcome the electron acceptor limitation in bacterial oxidative metabolism by means of using electrodes to enhance the biodegradation of pollutants in the environment. Our results revealed that the total degradation of C-SMZ reached 43.5% in short term batch laboratory scale experiments under reducing conditions (-400 mV vs. Ag/AgCl). Actually, SMZ mineralization was enhanced up to 10-fold in the early stages (after 2 weeks) in comparison with an electrode-free natural attenuation assay. Moreover, mineralization showed a dependence on electrode potential, with negligible results for conditions set to +400 mV vs Ag/AgCl. The impact of merging electrodes and microorganisms for manure bioremediation suggests a promising future for this emerging technology to treat polluted livestock wastes and prevent soil and groundwater pollution.
牲畜粪便是环境中抗生素的潜在来源。由于在动物肠道中不完全吸收和未代谢排泄，兽医中常用的磺胺甲恶唑 (SMZ) 会因其进入环境而作为土壤肥料使用。本研究的目的是评估在微生物电化学反应器（称为微生物电修复细胞（MERC））提供的新氧化还原情况下，粪便中 ¹³C 标记的 SMZ 的矿化作用。这些设备旨在通过使用电极来增强环境中污染物的生物降解，克服细菌氧化代谢中电子受体的限制。我们的结果表明，在短期批实验室规模实验中，在还原条件下（-400 mV 相对于 Ag/AgCl），¹³C-SMZ 的总降解达到 43.5%。实际上，与无电极的自然衰减测定相比，SMZ 的矿化作用在早期（2 周后）提高了 10 倍。此外，矿化作用取决于电极电位，对于设置为+400 mV 相对于 Ag/AgCl 的条件，几乎没有结果。将电极和微生物合并用于粪便生物修复的影响表明，这项新兴技术在处理受污染的牲畜废物和防止土壤和地下水污染方面具有广阔的前景。
