脱色希瓦氏菌/针铁矿还原去除甲硝唑及作用机制研究  

Reductive Removal of Metronidazole by Shewanella decolorationis/Goethite and the Mechanism Study

作　　者：史柯 李晓玲 寿建昕[2] 沈洁 董华平[1] SHI Ke;LI Xiaoling;SHOU Jianxin;SHEN Jie;DONG Huaping(School of Chemistry and Chemical Engineering,Shaoxing University,Shaoxing,Zhejiang 312000;School of Life Sciences,Shaoxing University,Shaoxing,Zhejiang 312000)

机构地区：[1]绍兴文理学院化学化工学院,浙江绍兴312000 [2]绍兴文理学院生命科学学院,浙江绍兴312000

出　　处：《绍兴文理学院学报》2023年第2期59-66,共8页Journal of Shaoxing University

基　　金：国家自然科学基金项目“生物炭对微生物/铁矿物还原氯代有机物的作用机制”(21677101);浙江省自然科学基金项目“生物炭对厌氧环境中异化铁还原协同氯代有机物转化降解的作用研究”(LY16B070004);浙江省自然科学基金项目“硫化铁矿物/零价铁还原去除地下水中重金属污染物的协同作用机制”(LY20B070004).

摘　　要：甲硝唑等硝基咪唑类抗生素具有毒性强、生物难降解等特性,已造成地下水等厌氧环境的污染.因此,甲硝唑在厌氧环境中的迁移转化,以及环境中共存的微生物、铁矿物对抗生素转化降解的作用机制,逐渐引起人们的关注.本文研究脱色希瓦氏菌S12(Shewanella decolorationis S12,S12)/针铁矿对甲硝唑的还原去除,分析抗生素去除过程中生物量、吸附Fe(II)、针铁矿表面晶型变化,并利用液相色谱-质谱联用(LC-MS)对甲硝唑的降解产物和途径进行检测分析.结果表明:S12胞外还原针铁矿产生吸附Fe(II)能够促进甲硝唑的还原去除,显著降低甲硝唑对S12的生物毒性.S12的胞外还原促使针铁矿表面向蓝铁矿的晶型转变,甲硝唑的还原明显促进了该矿物晶相的转变.LC-MS分析推测甲硝唑经硝基还原、脱氨基和脱羟基途径,降解为毒性较低的产物.通过本文研究,能够帮助我们弄清微生物/铁矿物对抗生素还原降解的作用机制.Nitroimidazole antibiotics such as metronidazole(MNZ)are strongly toxic and bio-refractory so that they have caused the pollution of anerobic environments including groundwater.Therefore,the migration and transformation of MNZ,and the effect of coexisting microorganism and Fe-bearing mineral on the transformation of antibiotics,have gradually drawn more attention.The study investigated the reductive removal of MNZ by Shewanella decolorationis S12(S12)/goethite,analyzed the changes in biomass,sorbed Fe(II)and surface crystal pattern of goethite,and traced the degraded products and pathway of MNZ by using LC-MS.The results show as follows:extracellular reduction of goethite by S12 produces more sorbed Fe(II)and promotes the reductive removal of MNZ,which obviously reduces the toxicity of MNZ towards S12.The surface crystal pattern of goethite transforms into vivianite during this process,and the reduction of MNZ contributes to this mineral crystal transition.The results of LC-MS speculate that MNZ is transformed into lower-toxic products through the pathway of nitro reduction,deamination and de-hydroxylation in turn.This study helps understand the mechanism of reductive degradation of antibiotics by microorganism/goethite more deeply.

关 键 词：脱色希瓦氏菌 针铁矿 抗生素 还原降解 晶相转变 

分 类 号：X506[环境科学与工程—环境工程]