好氧甲烷氧化系统氧氟沙星共代谢效能与微生物特征

Co-metabolic efficacy of ofloxacin in aerobic methane oxidation systems and their microbial characterization

氧氟沙星(ofloxacin,OFL)被广泛应用于疾病防治、畜禽养殖等领域,大量使用导致自然环境中存在残留的OFL。甲烷氧化菌在利用甲烷作为生长基质的同时,能通过共代谢的方式实现难降解有机物的生物降解。该研究针对含OFL废水,构建好氧甲烷氧化共代谢系统,开展系统中OFL去除效能和微生物特征研究。结果表明,好氧甲烷氧化系统能够实现OFL的有效降解,OFL的平均去除率可达80.15%。傅里叶红外光谱分析表明,系统能够有效去除氮磷污染物及芳香族化合物。宏基因组学分析表明,在属水平上存在15种甲烷氧化菌,以好氧甲烷氧化菌为主,总丰度为0.30%~0.56%;共检测出157种与甲烷代谢相关的功能基因,起主导作用的功能基因为E2.2.1.1/tktA/tktB、glyA/SHMT和xoxF;KEGG通路层级1共注释出6类代谢途径,KEGG通路层级2共注释出47条代谢途径。药物代谢-其他酶(Drug metabolism-other enzymes)、药物代谢-细胞色素P450(Drug metabolism-cytochrome P450)和细胞色素P450对外源性药物的代谢(Metabolism of xenobiotics by cytochrome P450)能够促进OFL的降解。相关结果可为抗生素及同类化合物的污染防治提供理论依据和技术支撑。

Ofloxacin(OFL)belongs to the quinolone antibiotics,which is widely used in the fields of disease control,livestock and poultry breeding,etc.Its large amount of use leads to the presence of residual OFL in the natural environment.Methane oxidising bacteria can achieve biodegradation of refractory organics through Cometabolism while using methane as a growth substrate.In this study,an aerobic methane oxidation cometabolism system was constructed for OFL-containing wastewater,and the OFL removal efficiency and the corresponding microbial characteristics were investigated.The results showed that the aerobic methane oxidation system was able to achieve the effective degradation of OFL,and the average removal rate of OFL could reach 80.15%.Fourier infrared spectroscopy analysis showed that the system could effectively remove nitrogen and phosphorus pollutants and aromatic compounds.Metagenomics analysis showed that there were 15 species of methane-oxidizing bacteria at genus level,the main bacteria are aerobic methane oxidizing bacteria,with a total abundance of 0.30%-0.56%;157 functional genes related to methane metabolism were detected,and the dominant functional genes were E2.2.1.1/tktA/tktB,glyA/SHMT and xoxF;6 metabolic pathways were annotated at KEGG pathway level 1,and 47 metabolic pathways were annotated at KEGG pathway level 2.Drug metabolism-other enzymes,drug metabolism-cytochrome P450,and metabolism of xenobiotics by cytochrome P450 could promote the degradation of OFL.The results can provide a theoretical basis and technical support for the pollution prevention of antibiotics and similar compounds.