生物电激活厌氧微生物降解甲硝唑路径及机制解析  

Pathway and Mechanism Analysis of Metronidazole Degradation through Bioelectrically Activated Anaerobic Microorganisms

作　　者：张泽楠 魏瑶丽 周爱娟[1] 李登飞 汪素芳 岳秀萍[1] ZHANG Ze‑nan;WEI Yao‑li;ZHOU Ai‑juan;LI Deng‑fei;WANG Su‑fang;YUE Xiu‑ping(College of Environmental Science and Engineering,Taiyuan University of Technology,Jinzhong 030600,China)

机构地区：[1]太原理工大学环境科学与工程学院,山西晋中030600

出　　处：《中国给水排水》2024年第19期94-101,共8页China Water & Wastewater

基　　金：国家自然科学基金资助面上项目(52470156);山西省重点研发项目(201903D321057)。

摘　　要：甲硝唑(MNZ)是一种应用广泛但难以在传统污水处理过程中被降解的抗生素。为此,以MNZ为唯一碳源,探究了生物电激活厌氧微生物对MNZ的降解性能,同时对反应体系的电化学性能、降解路径及阳极功能微生物群落进行了分析。结果表明,阳极微生物在经过150 d定向驯化后,反应10 d对MNZ的去除率可达到74.4%,最高电压和最大功率密度分别为0.072 V和7.61 mW/m^(2)。此外,循环伏安分析结果表明,阳极功能微生物群落的氧化电位与Rhodopseudomonas非常接近,推测体系中的电子传递可能是通过中间介体进行。进一步通过LC-MS对该体系中MNZ的降解产物进行了解析,推测可能存在的MNZ代谢产物有1-羟乙基2-甲基5-氨基咪唑、(2-甲基-5硝基咪唑-1-基)乙酸和1-羟乙基2-甲基咪唑等。16S rDNA高通量测序结果显示,Truepera、Mycobacterium、Aquamicrobium等功能微生物得到了大量富集而成为优势菌。生物电激活体系能够通过对厌氧微生物的定殖强化其对甲硝唑的降解作用,为研究抗生素类物质的生物降解提供了理论基础。Metronidazole(MNZ)is a prevalently utilized antibiotic that proves challenging to be degraded in conventional wastewater treatment processes.Therefore,with MNZ serving as the sole carbon source,the degradation performance of MNZ by bioelectrically activated anaerobic microorganisms was examined.Simultaneously,the electrochemical performance,degradation pathway and anode functional microbial community of the system were analyzed.After 150 days of targeted acclimation,the removal efficiency of MNZ could attain 74.4%within 10 days of the reaction.The maximum voltage and maximum power density were 0.072 V and 7.61 mW/m^(2)respectively.Additionally,the cyclic voltammetry analysis demonstrated that the oxidation potential of the anodic functional microbial community was highly similar to that of Rhodopseudomonas,indicating that electron transfer within the system might be conducted via an intermediary.The degradation products of MNZ in this system were further analyzed by LC-MS,and it was hypothesized that the possible metabolites of MNZ were 1‑hydroxyethyl 2‑methyl 5‑amino‑imidazole,(2‑methyl‑5‑nitroimidazole‑1‑yl)acetic acid and 1‑hydroxyethyl 2‑methylimidazole.The 16S rDNA highthroughput sequencing results indicated that functional bacteria such as Truepera,Mycobacterium and Aquamicrobium were enriched in high abundance and became the dominant bacteria.The bioelectrically activated system facilitated the degradation of metronidazole through the colonization of anaerobic microorganisms,thereby providing a theoretical foundation for the investigation of the antibiotics biodegradation.

关 键 词：生物电激活 厌氧微生物 甲硝唑 降解路径 生物阳极 

分 类 号：TU992[建筑科学—市政工程]