嗜热栖热菌降解氟喹诺酮类抗生素  

Biodegradation of fluoroquinolones by Thermus thermophilus

作　　者：潘兰佳 李杰[1] 李春星[1] 汪印[1] PAN Lanjia;LI Jie;LI Chunxing;WANG Yin(Key Laboratory of Urban Pollutant Conversion,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China)

机构地区：[1]中国科学院城市环境研究所,中国科学院城市污染物转化重点实验室,厦门361021

出　　处：《环境工程学报》2020年第4期1092-1102,共11页Chinese Journal of Environmental Engineering

基　　金：美丽中国生态文明建设科技工程专项(XDA23030301,XDA23020500);中日政府间国际科技创新合作重点项目(2016YFE0118000)。

摘　　要：氟喹诺酮类抗生素在各种环境基质中积累造成的生态和耐药基因污染等问题已引起广泛的关注。为了能够有效去除环境中氟喹诺酮类抗生素污染并且探究其生物代谢途径,利用嗜热菌Thermus sp.C419在高温(70℃)条件下降解2种典型的氟喹诺酮类抗生素(诺氟沙星和恩诺沙星),分析了菌株C419对这2种药物在单一和混合添加时的降解特性;通过UPLC-MS/MS检测了其相关的降解产物,并推测了可能的代谢途径;利用平板扩散法对生物降解后的氟喹诺酮类药物进行抑菌活性测定。结果表明:氟喹诺酮类化合物可被菌株C419有效降解,降解率为60%~80%;该生物降解过程符合一级动力学模型,培养基中氟喹诺酮类化合物浓度越高,降解率越高,降解半衰期越短;菌株C419对诺氟沙星的生物降解有3条可能的降解途径和7种降解产物,对恩诺沙星的生物降解有4条可能的降解途径和6种降解产物。此外,与2种药物的母体化合物相比,生物降解后药物对不同细菌的抗菌活性均有一定程度的降低,这说明嗜热菌株C419在热环境中去除氟喹诺酮类污染物方面可能会具有良好的实用性和应用前景。The problems of environmental matrices pollution and resistance genes generation caused by fluoroquinolones accumulation seriously affect human health, thus its removal and transformation have attracted broad attention. In order to effectively remove fluoroquinolone antibiotics from environment and explored their bio-metabolic pathway, a thermophilic bacterium(Thermus sp. strain C419) was used to biodegrade two representative fluoroquinolones(norfloxacin and enrofloxacin) at high temperature of 70 ℃, the degradation characteristics of these two fluoroquinolone alone and their mixture by C419 were analyzed. The degradation products were detected by UPLC-MS/MS to predict the possible metabolic pathway, the antibacterial activity of the biodegraded fluoroquinolones was test by using disk diffusion susceptibility assays. The results showed that fluoroquinolones could be degraded effectively by strain C419 with a degradation efficiency of 60%~75%, the biodegradation process followed the first order kinetic model. Higher fluoroquinolones concentration resulted in higher degradation efficiency and shorter degradation half-life period. The norfloxacin biodegradation by strain C419 occurred via three pathways and yielded seven biodegradation metabolites, while the enrofloxacin biodegradation occurred via four pathways and yielded six biodegradation metabolites. In addition, the biodegrading-metabolites of norfloxacin and enrofloxacin presented attenuated antibacterial activities. The obtained results indicated that the thermophilic fluoroquinolone-degrading Thermus sp. strain C419 presented useful and meaningful application prospect in removing fluoroquinolone contaminants especially from thermal environments.

关 键 词：抗生素降解 氟喹诺酮 嗜热微生物 代谢产物 生物降解途径 抗菌活性 

分 类 号：X592[环境科学与工程—环境工程]