Ag^+在含Cl^-培养基中的毒性初探  

Probe to the toxicity sources of Ag^+ in the microbial media

作　　者：宋春磊[1] 方章顺 王大力[1,3] 秦孟楠 林志芬[1] 陈瑞[1] 

机构地区：[1]同济大学环境科学与工程学院,上海200092 [2]安徽师范大学环境科学与工程学院,安徽芜湖234000 [3]同济大学土木工程学院博士后流动站,上海200092

出　　处：《安全与环境学报》2017年第4期1604-1608,共5页Journal of Safety and Environment

基　　金：国家自然科学面上基金项目(21377096;21577105);同济大学污染控制与资源化研究国家重点实验室自主研究项目(PCRRY11003);同济大学英才(攀登)计划项目(0400219287);上海市科学技术委员会项目(14DZ2261100);中国博士后科学基金面上项目(2016M600332)

摘　　要：纳米银(Ag NPs)和硝酸银(AgNO_3)的毒性研究已成为环境科学的焦点问题之一。毒性测试时LB培养基中的Cl^-势必会对Ag^+的毒性产生影响。为了探究Cl^-对Ag^+的溶解态及毒性的影响,计算了常温(25℃)和试验条件(37℃)下含1%NaCl的LB培养基中Ag Cl1-xx各组分的生成量及在体系中所占比例,测定了不同NaCl质量分数的LB培养基中AgNO_3对革兰氏阳性菌(B.subtilis)和阴性菌(E.coli)的毒性。结果表明,AgNO_3在含NaCl体系中溶解态银主要为Ag Cl1-xx,而Ag^+未达到有毒的浓度,且随NaCl质量分数增加,AgNO_3的毒性不断增大。因此认为毒性试验中实际发挥毒性作用的是Ag Cl1-xx,尤其是Ag Cl^-2。The present paper intends to make a preliminary study of the impact of Cl-on the dissolved state of Ag＋,the yields and percentages of AgC l1-x xin the LB media in different concentrations of NaCl based on the chemical equilibrium under the experimental temperature of 37 ℃ and the normal temperature of 25 ℃,respectively. In addition,we have also done experimental tests on the toxicity of AgNO3 in different concentrations in LB media with different concentration rates of NaCl to gram positive bacteria（ Bacillus subtilis） and gram negative bacteria（ Escherichia coli） basedon the condition of the light absorption value at the wavelength of600 nm（ OD600） after being cultured for 12 h at the temperature of 37 ℃. At the same time,we have also determined the toxicity of Ag＋in LB medium,in which NaCl has been replaced by the isotonic concentration of NaN O3. The results of our experiments show that the concentration of Ag＋tends to decrease gradually with the increase of the concentration of NaCl in LB medium,whereas the EC50 of AgNO3 both to Bacillus subtilis and Escherichia coli tend to decrease evidently,which implies that the toxicity of AgNO3 has been enhanced. Besides,the dissolved state of Ag remains mainly in the form of AgC l1-x xin the normal LB medium,and the main concentration of Ag＋in the LB medium with NaCl may not reach the toxic level according to the toxicity results of AgNO3 in the LB medium with NaCl replaced by NaN O3.Therefore,it can be inferred that for the normal LB medium,the toxicity of AgNO3 should not come from Ag＋,but,rather from AgC l1-x x; implying that it turns out to result in a linear structure of AgCl-2,which can make it easier for AgCl-2to enter into the cells. Thus,AgCl-2should be considered as the chief factor which results in the toxicity of Ag＋in LB medium and in the water environment with Cl-being contained in.

关 键 词：环境学 纳米银毒性 硝酸银 氯化钠 氯离子 

分 类 号：X131.2[环境科学与工程—环境科学]