Guo Zhi, Chen Guiqiu, Zeng Guangming, Yan Ming, Huang Zhenzhen, Jiang Luhua, Peng Chuan, Wang Jiajia, Xiao Zhihua
College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
Chemosphere. 2017 Mar;171:318-323. doi: 10.1016/j.chemosphere.2016.12.077. Epub 2016 Dec 18.
Increasing amounts of silver nanoparticles (AgNPs) are expected to enter the ecosystems where their toxicity in the environment is proposed. In this study, we exploited the effect of environmental anions on AgNP toxicity. AgNP were mixed with various environmental anions, and then exposed to Escherichia coli to determine the effect on bacteria growth inhibition. The results demonstrated that AgNP are not always toxic in the presence of sulfide, but can stimulate microbial growth at certain concentrations. Environmental chloride and phosphate anions cannot induce the stimulation because of their weak capacity to control the release of Ag from AgNP. Ag that released from AgNP is proven to be responsible for AgNP toxicity. Moreover, we found that AgNP toxicity is dependent on sulfuration rate. At the same sulfuration rate, AgNP shows an identical pattern of toxicity. This study indicates that only sulfide of the tested environmental anions can induce AgNP stimulation to microbial growth in a sulfuration rate dependent pattern and the toxicity originate from Ag that released from AgNP.
预计越来越多的银纳米颗粒（AgNP）会进入生态系统，其在环境中的毒性也由此引发关注。在本研究中，我们探究了环境阴离子对AgNP毒性的影响。将AgNP与各种环境阴离子混合，然后暴露于大肠杆菌中，以确定对细菌生长抑制的影响。结果表明，在有硫化物存在的情况下，AgNP并非总是有毒的，而是在一定浓度下能刺激微生物生长。环境中的氯离子和磷酸根阴离子由于控制AgNP中银释放的能力较弱，无法引发这种刺激作用。已证实从AgNP释放的银是造成AgNP毒性的原因。此外，我们发现AgNP的毒性取决于硫化速率。在相同的硫化速率下，AgNP表现出相同的毒性模式。本研究表明，在所测试的环境阴离子中，只有硫化物能以依赖硫化速率的模式诱导AgNP对微生物生长产生刺激作用，且毒性源自从AgNP释放的银。
