title: Are silver nanoparticles always toxic in the presence of environmental anions?
abstract: 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.
authors.affiliation: 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.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Guo
authors.affiliation: 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. Electronic address: gqchen@hnu.edu.cn.
authors.forename: Guiqiu
authors.initials: G
authors.lastname: Chen
authors.affiliation: 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. Electronic address: zgming@hnu.edu.cn.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
authors.affiliation: 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.
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.affiliation: 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.
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Huang
authors.affiliation: 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.
authors.forename: Luhua
authors.initials: L
authors.lastname: Jiang
authors.affiliation: 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.
authors.forename: Chuan
authors.initials: C
authors.lastname: Peng
authors.affiliation: 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.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, Hunan, 410128, PR China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Xiao
mesh_terms: D004777:Environment; D004785:Environmental Pollutants / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D012834:Silver / Q000737:chemistry / Q000633:toxicity*; D013440:Sulfides / Q000494:pharmacology*
chemical_list: D004785:Environmental Pollutants; D013440:Sulfides; D012834:Silver
keywords: Environmental anion; Ligand; Silver nanoparticle; Sulfide; Toxicity