Widespread pesticide use in agriculture is a major source of soil pollution, driving biodiversity loss and posing serious threads to human health. The recalcitrant nature of most of these pesticides demands for effective remediation strategies. In this study, we assess the ability of soil microbial fuel cell (SMFC) technology to bioremediate soil polluted by the model pesticide atrazine. To elucidate the degradation mechanism and consequently define effective implementation strategies, we provide the first comprehensive investigation of the SMFC performance, in which the monitoring of the electrochemical performance of the system is combined with Quadrupole Time-of-Flight (QTOF) mass spectrometry and microbial analyses. Our results show that, while both SMFC and natural attenuation lead to a reduction on atrazine levels, the SMFC modulates the activity of different microbial pathways. As a result, atrazine degradation by natural attenuation leads to high levels of deisoproylatrazine (DIPA), a very toxic degradation metabolite, while DIPA levels in soil treated by SMFC remain comparatively low. The beta diversity and differential abundance analyses revealed how the microbial community evolves over time in the SMFCs degrading atrazine, demonstrating the enrichment of electroactive taxa on the anode, and the enrichment of a mixture of electroactive and atrazine-degrading taxa at the cathode. The detection and taxonomic classification of peripheral atrazine degrading genes, , and , was carried out in combination with the differential abundance analysis. Results revealed that these genes are likely harboured by members of the order enriched at the cathode, thus promoting atrazine degradation via the conversion of hydroxyatrazine (HA) into N-isopropylammelide (NIPA), as confirmed by mass spectrometry data. Overall, the comprehensive approach adopted in this work, provides fundamental insights into the degradation pathways of atrazine in soil by SMFC technology, which is critical for practical applications, thus suggesting an effective approach to advance research in the field.

中文翻译：

---

评估土壤微生物燃料电池对土壤中莠去津去除的影响


农业中广泛使用农药是土壤污染的一个主要来源，导致生物多样性丧失，严重影响人类健康。大多数农药的顽固性需要有效的修复策略。在这项研究中，我们评估了土壤微生物燃料电池（SMFC）技术对受模型农药莠去津污染的土壤进行生物修复的能力。为了阐明降解机制并从而确定有效的实施策略，我们首次对 SMFC 性能进行了全面研究，其中系统电化学性能的监测与四极杆飞行时间 (QTOF) 质谱和微生物分析相结合分析。我们的结果表明，虽然 SMFC 和自然减毒都会导致莠去津水平降低，但 SMFC 会调节不同微生物途径的活性。因此，自然衰减降解莠去津会产生高浓度的去异丙莠去津 (DIPA)，这是一种毒性很强的降解代谢物，而经 SMFC 处理的土壤中 DIPA 水平仍然相对较低。 β多样性和差异丰度分析揭示了降解阿特拉津的 SMFC 中微生物群落如何随时间演变，证明了阳极上电活性类群的富集，以及阴极上电活性和阿特拉津降解类群的混合物的富集。结合差异丰度分析，对外周莠去津降解基因 、 、 进行检测和分类。 结果表明，这些基因可能由在阴极富集的目成员携带，从而通过将羟基莠去津 (HA) 转化为 N-异丙酰胺 (NIPA) 来促进莠去津降解，正如质谱数据所证实的那样。总的来说，这项工作采用的综合方法为 SMFC 技术在土壤中莠去津的降解途径提供了基本的见解，这对于实际应用至关重要，从而为推进该领域的研究提供了一种有效的方法。