The minimum inhibitory concentration (MIC) assay with Escherichia coli: An early tier in the environmental hazard assessment of nanomaterials?
Ecotoxicol Environ Saf
; 162: 633-646, 2018 Oct 30.
Article
en En
| MEDLINE
| ID: mdl-30033160
There are now over a thousand nano-containing products on the market and the antibacterial properties of some nanomaterials has created interest in their use as cleaning agents, biocides and disinfectants. Engineered nanomaterials (ENMs) are being released into the environment and this raises concerns about their effects on microbes in the receiving ecosystems. This study evaluated the bacterial toxicity of a wide range of nanomaterials with different surface coatings on Escherichia coli K-12 MG1655. The minimum inhibitory concentration (MIC) assay, which quantifies the threshold for growth inhibition in suspensions of bacteria, was used to rank the toxicity of silver (Ag), cupric oxide (CuO), cadmium telluride (CdTe) quantum dots, titanium dioxide (TiO2), nanodiamonds and multi-walled carbon nanotubes (MWCNTs). Bacteria were exposed for 12â¯h at 37⯰C to a dilution series of the test suspensions in 96-well plates. The precision and accuracy of the method was good with coefficients of variation <â¯10%. In terms of the measured MIC values, the toxicity order of the ENMs was as follows: CdTe quantum dots ammonium-coated, 6â¯mgâ¯L-1 >â¯Ag nanoparticles, 12â¯mgâ¯L-1 >â¯CdTe quantum dots carboxylate-coated, 25â¯mgâ¯L-1 >â¯CdTe quantum dots polyethylene glycol-coated, 100â¯mgâ¯L-1. The MIC values were above the highest test concentration used (100â¯mgâ¯L-1) for CuO, TiO2, nanodiamonds and MWCNTs, indicating low toxicity. The MIC assay can be a useful tool for the initial steps of ENMs hazard assessment.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Nanoestructuras
/
Escherichia coli
Idioma:
En
Revista:
Ecotoxicol Environ Saf
Año:
2018
Tipo del documento:
Article
Pais de publicación:
Países Bajos