Comparative cytotoxicity of nanoparticles and ions to Escherichia coli in binary mixtures

Publication date: Available online 14 July 2016
Source:Journal of Environmental Sciences
Author(s): Swati Srivastava, Arun Kumar
The objective of this study was to understand toxicity of mixture of nanoparticles (NPs) (ZnO and TiO2) and their ions to Escherichia coli. Results indicated the decrease in percentage growth of E.coli with the increase in concentration of NPs both in single and mixture setups. Even a small concentration of 1mg/L was observed to be significantly toxic to E.coli in binary mixture setup (exposure concentration: 1mg/L ZnO and 1mg/L TiO2; 21.15% decrease in plate count concentration with respect to control). Exposure of E.coli to mixture of NPs at 1000mg/L (i.e., 1000mg/L ZnO and 1000mg/L TiO2) resulted in 99.63% decrease in plate count concentration with respect to control. Toxic effects of ions to E.coli were found to be lesser than their corresponding NPs. The percentage growth reduction was found to be 36% for binary mixture of zinc and titanium ions at the highest concentration (i.e., 803.0mg/L Zn and 593.3mg/L Ti where ion concentrations are equal to the Zn ions present in 1000mg/L ZnO NP solution and Ti⁺⁴ ions present in 1000mg/L TiO2 NP solution). Nature of mixture toxicity of the two NPs to E.coli was found to be antagonistic. The alkaline phosphatase (Alp) assay indicated that the maximum damage was observed when E.coli was exposed to 1000mg/L of mixture of NPs. This study tries to fill the knowledge gap on information of toxicity of mixture of NPs to bacteria which has not been reported earlier.

Graphical abstract

from #Ἀθηνᾶ via ola Kala on Inoreader http://ift.tt/29I3Ab0
via IFTTT