载铅高硅质粉尘对大肠杆菌壁膜的损伤作用机制  

The Role of Lead Coated onto High-Silica Dust in the Mechanism of E.coli Wall Membrane Damage

作　　者：马杰[1] 董发勤[1,2] 霍婷婷[1] 赵玉连[1] 李苗 李刚[1] 孟繁斌 MA Jie;DONG Fa-qin;HUO Ting-ting;ZHAO Yu-lian;LI Miao;LI Gang;MENG Fan-bin(School of Environment and Resource,Southwest University of Science and Technology,Mianyang 621010,China;Key Laboratory of Solid Waste Treatment and Resource Recycle,Ministry of Education,Mianyang 621010,China;School of Material Science and Engineering,Southeast University of Science and Technology,Mianyang 621010,China;School of Life Science and Engineering,Southeast University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学环境与资源学院,四川绵阳621010 [2]固体废物与资源化教育部重点实验室,四川绵阳621010 [3]西南科技大学材料科学与工程学院,四川绵阳621010 [4]西南科技大学生命科学与工程学院,四川绵阳621010

出　　处：《光谱学与光谱分析》2018年第5期1492-1498,共7页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(41130746;41602033);西南科技大学创新基金项目(17ycx040)资助

摘　　要：大气颗粒物与微生物共存时的健康效应受到了越来越多的关注。以大气颗粒物中石英与重金属铅为研究对象,粉尘浓度为1.6g·L^(-1),制备载带不同浓度铅高硅质粉尘,以人体常见菌—大肠杆菌为受试对象,探讨载铅高硅质粉尘对大肠杆菌细胞壁膜损伤的机理。采用噻唑蓝(MTT)测定微生物的细胞活力后发现,与对照组相比,大肠杆菌与载铅石英粉尘作用2h后,细胞活力表现出单一铅离子组大于载铅石英粉尘组,并且呈现重金属剂量效应。PI的摄入量测试表明,高浓度载铅粉尘组中摄入量分别高出对照组36%与46%,单一重金属组摄入量也有较高的增长,而激光共聚焦显微镜观察图中,染毒组均出现不同程度的红色荧光,可以发现载铅石英粉尘作用后的细菌细胞壁膜通透性明显升高,利用探针标记,采取荧光分光光度法测定荧光强度显示胞内和溶液中活性氧逐渐增多,载铅粉尘组(Q+Pb-2,Q+Pb-3)胞内ROS分别较对照组高出2倍和2.5倍,参照前人研究,发现溶液中ROS变化主要与重金属离子在其表面结合态数量决定。综合分析,活性氧在诱使细胞膜损伤过程中起到决定性作用。红外表征中,细胞膜表面磷酸二脂基团、蛋白质甲基振动及酰胺带等基团与载铅石英粉尘作用后均发生明显峰位偏移,均与载铅粉尘发生较强相互作用,一定程度上影响细胞壁膜完整性。综上,重金属与粉尘共同作用使得细胞膜通透性发生变化,细胞壁膜的完整性改变,影响细胞活力,最终导致细菌死亡,活性氧及重金属等的作用导致细胞膜的损伤可能是载重金属高硅质粉尘的一种毒性作用机制。Health effects of coexistence between atmospheric particulate matter and microbial have received more and more attention.In this paper,quartz and lead in atmospheric particles were used as the object to prepare silica dust with lead,which has different concentrations.The dust concentration was 1.6 g·L-1.All the work is to explore the mechanism of lead coated onto high-silica dust on cell wall/membrane injury of Escherichia coli.MTT(thiazolyl blue)was used to determine the cell viability of microbes.Compared with the control group,the cell viability of lead ion group was higher than that of the group of lead coated onto quartz dust after E.coli was treated for 2 h,it also presented a Dose effect.In PI intake test,it showed that intensity in the high concentration lead dust group was 36%and 46%higher than that in the control group,and intensity in the heavy metal group was the same as that in the former.For the Confocal laser scanning microscope,the results showed that the red fluorescence intensity of the experiment group was significantly higher than that of the control group,suggesting that the permeability of the cell membrane of the bacteria has obviously increased after treated with Pb coated onto quartz dust.The fluorescence intensity measured by fluorescence spectrophotometry showed that the intensity of ROS in the solution and cell both increased.Pb coated onto quartz dust group(Q+Pb-2,Q+Pb-3)were twice and 2.5 times higher than those in the control group,respectively.According to the previous study,the change of ROS in the solution is mainly determined by the amount of the binding state of heavy metal ions on the quartz surface.On the basis of above phenomenon,we found that Reactive Oxygen Species play an important role in inducing cell membrane damage.In the infrared characterization,the effects of Pb and Pb coated onto quartz dust on E.coli surface groups mainly attach importance to phosphodiester group,protein methylation and the amide band of the cell membrane.Those groups showed a significant peak s

关 键 词：大肠杆菌 载铅石英粉尘 壁膜损伤 活性氧 细胞膜 

分 类 号：Q939.9[生物学—微生物学]