Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, China; Department of Biology, Taiyuan Normal University, Shanxi 030619, China.
Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, China.
J Hazard Mater. 2021 Apr 15;408:124880. doi: 10.1016/j.jhazmat.2020.124880. Epub 2020 Dec 16.
Microbial fuel cells (MFCs) are capable of removing tetracycline in soils, in which the degradation efficiency of tetracycline is hindered by its strong adsorption capacity. Phosphate was chosen as a competitor for tetracycline adsorption to improve its removal rate in soil MFCs. The results showed that 42-50% of tetracycline was degraded within 7 days, which was 42-67% higher than open-circuit treatments. Compared with closed-circuit treatments without phosphate addition, the removal efficiencies of tetracycline after phosphate addition increased by 19-25% on day 51, and accumulated charge outputs were enhanced by 31-52%, while the abundance of antibiotic resistance genes decreased by 19-27%. Like Geobacter, the abundance of Desulfurispora and Anaeroomyxobacter in the anode showed similar tendencies with current densities, suggesting their dominant roles in bioelectricity generation. Gemmatimonadetes bacterium SCN 70-22, Azohydromonas australica, Steroidobacter denitrificans and Gemmatirosa kalamazoonesis were found to be potential electrotrophic microbes in the cathode. The expressed flavoprotein 2,3-oxidoreductase, quinol oxidase and fumarate reductase might have promoted the transfer efficiency of electrons from cathodes to cells, which finally accelerated the biodegradation rate of tetracycline in addition to the polyphenol oxidase. This study provides an insight into functional enzyme genes in the soil microbial electrochemical remediation.
微生物燃料电池（MFCs）能够去除土壤中的四环素，而四环素的降解效率受到其强吸附能力的阻碍。选择磷酸盐作为四环素吸附的竞争物，以提高其在土壤 MFC 中的去除率。结果表明，四环素在 7 天内降解了 42-50%，比开路处理高出 42-67%。与不加磷酸盐的闭路处理相比，添加磷酸盐后第 51 天四环素的去除效率提高了 19-25%，累积电荷输出提高了 31-52%，而抗生素抗性基因的丰度则降低了 19-27%。与地杆菌一样，阳极中脱硫弧菌和厌氧粘球菌的丰度与电流密度呈相似趋势，表明它们在生物电能产生中起主导作用。在阴极中发现了 Gemmatimonadetes 细菌 SCN 70-22、澳大利亚氨单胞菌、脱氮硫杆菌和 Kalamazoonesis gemmatis。表达的黄素蛋白 2,3-氧化还原酶、醌氧化酶和延胡索酸还原酶可能促进了电子从阴极向细胞的传递效率，除多酚氧化酶外，还加速了四环素的生物降解速率。本研究为土壤微生物电化学修复中的功能酶基因提供了深入了解。
