肠杆菌Enterobacteria sp.X57富集铀(Ⅵ)的初探  

Preliminary Exploration of U(Ⅵ)Enrichment by Enterobacteria sp.X57

作　　者：曾倩 朱婷[1,2] 李飞泽 杨远友[1] 杨吉军[1] 兰图[1] 廖家莉 刘宁[1] ZENG Qian;ZHU Ting;LI Feize;YANG Yuanyou;YANG Jijun;LAN Tu;LIAO Jiali;LIU Ning(Key Laboratory of Radiation Physics and Technology of Ministry of Education,Institute of Nuclear Science and Technology,Sichuan University,Chengdu 610064,China;Key Laboratory of Biological Resource and Ecological Environment of Ministry of Education,College of Life Sciences,Sichuan University,Chengdu 610064,China)

机构地区：[1]四川大学原子核科学技术研究所辐射物理及技术教育部重点实验室,四川成都610064 [2]四川大学生命科学学院生物资源与生态环境教育部重点实验室,四川成都610064

出　　处：《原子能科学技术》2022年第7期1258-1266,共9页Atomic Energy Science and Technology

基　　金：国家自然科学基金(21876123)。

摘　　要：为开发可用于铀污染环境修复的优势微生物,本文考察了一株从铀污染场所分离的新型肠杆菌Enterobacter sp. X57在不同的环境因素下对铀的富集行为,并结合相关的表征探索了可能的生物富集机理。结果表明,Enterobacter sp. X57对铀的富集依赖于细菌的代谢活性,且受接触时间、pH值、温度、初始铀(Ⅵ)浓度以及共存离子等多种因素的共同影响。在铀初始浓度100 mg/L、温度303 K、pH=7.00条件下,Enterobacter sp. X57对铀的最大富集量约为175.52 mg/g(干重)。动力学研究结果表明,Enterobacter sp. X57富集铀的过程存在化学吸附、粒内扩散等多个阶段。傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱(EDS)以及X射线衍射(XRD)结果表明,溶液中的铀(Ⅵ)与细胞中的羧基、氨基、磷酰基等官能团发生络合,并同时扩散至胞内的细胞质膜上形成铀-磷酸盐矿物。上述结果表明,Enterobacter sp. X57对铀的富集是通过生物吸附和生物沉积矿化的协同作用实现的。In this work,the enrichment behavior and mechanisms of U(Ⅵ)by Enterobacter sp.X57,a novel bacterial strain isolated from uranium contaminated sites,under different environmental conditions were investigated to develop superior microorganisms for uranium-contaminated environments bioremediation.The results show that the enrichment of U(Ⅵ)by Enterobacter sp.X57 depended on the cellular metabolic activity,and was also influenced by the contact time,pH,temperature,initial U(Ⅵ)concentration and coexisting ions.Under the conditions of initial concentration of U(Ⅵ)of 100 mg/L,temperature of 303 K and pH=7.00,the maximum enrichment capacity of Enterobacter sp.X57 is about 175.52 mg/g(dry weight).Kinetics results indicate that the enrichment process of U(Ⅵ)by Enterobacter sp.X57 involves chemical adsorption and intra particle diffusion.The analyses of FT-IR,SEM,TEM,EDS and XRD further reveal that uranyl in solution could rapidly bond with the carboxyl,amino,and phosphoryl groups of Enterobacter sp.X57,and diffuse into cell periplasmic space,depositing as U(Ⅵ)-phosphate minerals on the cell plasma membrane.The results indicate that the enrichment of uranium by enterbacter sp.X57 is realized by the synergism of biosorption and biomineralization.

关 键 词：肠杆菌 铀(Ⅵ) 富集 生物吸附 生物矿化 铀-磷酸盐矿物 

分 类 号：X523[环境科学与工程—环境工程] TQ424[化学工程]