Oliveira Bruna M, Zaiat Marcelo, Oliveira Guilherme H D
a Laboratory of Biological Processes, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering , University of São Paulo (USP) , São Carlos , São Paulo , Brazil.
J Environ Sci Health B. 2019;54(4):263-270. doi: 10.1080/03601234.2018.1553909. Epub 2019 Jan 10.
Biodegradation of organic micropollutants is likely to occur due to cometabolism by particular microbial groups. In an effort to identify the stages of anaerobic digestion potentially involved in the biodegradation of the veterinary antimicrobial sulfamethazine (SMZ), the influence of selected carbon sources (sucrose, glucose, fructose, ethanol, meat extract, cellulose, soluble starch, soy oil, acetic acid, propionic acid and butyric acid) on SMZ removal by anaerobic sludge was evaluated in short-term batch experiments. Adsorption to the granular sludge constituted a significant removal mechanism, accounting for 39% of SMZ removal in control experiments. The presence of glucose, fructose, sucrose and meat extract exerted an inducing effect on SMZ degradation, resulting in removal efficiencies of 54, 53, 58 and 61%, respectively, indicating the occurrence of cometabolism. Time courses of sucrose and meat extract degradation revealed markedly distinct organic acid profiles but resulted in similar SMZ removals. Temporal profiles of acetic and propionic acid degradation were not associated with SMZ removal, as changes in SMZ concentration were observed even after the organic acids had been completely removed. The experimental results suggest that SMZ cometabolism is not associated to sucrose hydrolysis, acetoclastic methanogenesis and acetogenesis from propionic acid.
由于特定微生物群体的共代谢作用，有机微污染物可能会发生生物降解。为了确定厌氧消化过程中可能参与兽用抗菌剂磺胺二甲嘧啶（SMZ）生物降解的阶段，在短期批次实验中评估了选定碳源（蔗糖、葡萄糖、果糖、乙醇、肉提取物、纤维素、可溶性淀粉、大豆油、乙酸、丙酸和丁酸）对厌氧污泥去除SMZ的影响。颗粒污泥的吸附是一种重要的去除机制，在对照实验中占SMZ去除量的39%。葡萄糖、果糖、蔗糖和肉提取物的存在对SMZ降解有诱导作用，去除效率分别为54%、53%、58%和61%，表明发生了共代谢。蔗糖和肉提取物降解的时间进程显示出明显不同的有机酸谱，但导致的SMZ去除效果相似。乙酸和丙酸降解的时间分布与SMZ去除无关，因为即使在有机酸完全去除后仍观察到SMZ浓度的变化。实验结果表明，SMZ共代谢与蔗糖水解、乙酸裂解产甲烷以及丙酸产乙酸无关。
