Laboratory of Natural Organic Matter, Department of Chemistry, Federal University of Sergipe, 49100-000, São Cristóvão, SE, Brazil.
Laboratory of Forensic Chemistry, Scientific Police, Secretary of Public Security, 49107-230, São Cristóvão, SE, Brazil.
J Environ Manage. 2024 Nov;370:122797. doi: 10.1016/j.jenvman.2024.122797. Epub 2024 Oct 9.
Glyphosate (GLY), a globally-used organophosphate herbicide, is frequently detected in various environmental matrices, including water, prompting significant attention due to its persistence and potential ecological impacts. In light of this environmental concern, innovative remediation strategies are warranted. This study utilized Serratia sp. AC-11 isolated from a tropical peatland as a biocatalyst in a microbial fuel cell (MFC) coupled with a homogeneous electron-Fenton (EF) process to degrade glyphosate in aqueous medium. After coupling the processes with a resistance of 100 Ω, an output voltage value of 0.64 V was obtained and maintained stable throughout the experiment. A bacterial biofilm of Serratia sp. AC-11 was formed on the carbon felt electrode, confirmed by attenuated total reflectance-Fourier transformed infrared (ATR-FTIR) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). In the anodic chamber, the GLY biodegradation rate was 100% after 48 h of experimentation, with aminomethylphosphonic acid (AMPA) remaining in the solution. In the cathodic chamber, the GLY degradation rate for the EF process was 69.5% after 48 h experimentation, with almost all of the AMPA degraded by the in situ generated hydroxyl radicals. In conclusion, the results demonstrated that Serratia sp. AC-11 not only catalyzed the biodegradation of glyphosate but also facilitated the generation of electrons for subsequent transfer to initiate the EF reaction to degrade glyphosate. This dual functionality emphasizes the unique capabilities of Serratia sp. AC-11, it as an electrogenic microorganism with application in innovative bioelectrochemical processes, and highlighting its role in sustainable strategies for environmental remediation.
草甘膦（GLY）是一种全球广泛使用的有机磷除草剂，经常在各种环境基质中被检测到，包括水，由于其持久性和潜在的生态影响而引起了极大的关注。鉴于这种环境问题，需要创新的修复策略。本研究利用从热带泥炭地中分离出的鞘氨醇单胞菌 AC-11 作为生物催化剂，在微生物燃料电池（MFC）中与均相电子芬顿（EF）过程耦合，以降解水中的草甘膦。在将这些过程与 100 Ω 的电阻耦合后，获得了 0.64 V 的输出电压值，并在整个实验过程中保持稳定。鞘氨醇单胞菌 AC-11 的细菌生物膜形成在碳纤维毡电极上，通过衰减全反射傅里叶变换红外（ATR-FTIR）和带有能量色散光谱（SEM-EDS）的扫描电子显微镜得到证实。在阳极室中，经过 48 小时的实验，草甘膦的生物降解率达到 100%，溶液中仍残留氨甲基膦酸（AMPA）。在阴极室中，EF 过程的草甘膦降解率在 48 小时实验后达到 69.5%，几乎所有的 AMPA 都被原位生成的羟基自由基降解。总之，结果表明，鞘氨醇单胞菌 AC-11 不仅催化了草甘膦的生物降解，而且促进了电子的生成，随后将电子转移到引发 EF 反应以降解草甘膦。这种双重功能强调了鞘氨醇单胞菌 AC-11 的独特能力，它作为一种发电微生物，可应用于创新的生物电化学过程，并突出了它在可持续环境修复策略中的作用。
