Toxicity effects of four typical nanomaterials on the growth of Escherichia coli, Bacillus subtilis and Agrobacterium tumefaciens

Abstract

To offer an insight into the toxicity of nanomaterials (NM) on the growth of bacteria, Escherichia coli (E. coli), Bacillus subtilis (B. subtilis) and Agrobacterium tumefaciens (A. tumefaciens) were exposed to nanoAu, nano-Ag, nano-Fe and fullerene (C 60 ) in this study. As an effective bactericide, nano-Ag induced high toxicity on these three bacteria; C 60 could inhibit their growth; however, B. subtilis and E. coli could recover as exposure time extended. Nano-Au and nano-Fe had hardly any effect on three bacteria. A. tumefaciens showed the lowest resistance and slowest growth rate during exposure. Images obtained by scanning electron microscope (SEM) revealed that nano-Ag could cause damage to the cell structure of three bacteria at 1 lg/mL. Slight damage on E. coli was found when exposed to C 60 , whereas no obvious physical damage was found after exposure to nano-Au or nano-Fe. It is assumed that surface activities of NM might be responsible for the different toxic effects on these bacteria.

A fullerene colloidal suspension stimulates the growth and denitrification ability of wastewater treatment sludge-derived bacteria

“…conditions (Fortner et al, 2005;Lyon et al, 2006;Lyon and Alvarez, 2008;Aoshima et al, 2009;Chae et al, 2009;Letts et al, 2011;Dai et al, 2012;Hancock et al, 2012;Wang et al, 2012). Oxygen is considered to be a prerequisite for the bioactive effect of colloidal fullerene on bacteria under aerobic conditions (Yamakoshi et al, 2003;Markovic et al, 2007).…”

Transport of Surface-modified Carbon Nanotubes through a Soil Column

“…They have unique properties, which have accelerated their use in many applications, such as electronics, optics, cosmetics, and biomedical technology (e.g., composite materials) 5 . With increased use, there is also an increased risk to human exposure and effect on health as well as adverse ecological consequences following CNT and other carbon based nanomaterials disposal to the environment [5][6][7][8] .…”

“…On the other hand, to reduce environmental risks, there is a need for studies focusing on how to immobilize the CNTs in order to avoid their entrance into aquifers and drinking water resources 11 . Recent studies have reported the toxic effect of CNTs on living organisms and also risks to ecosystems in terms of CNTs entering and accumulating in the food chains, since CNTs are hard to biodegrade 5,8 . Even with barrier systems in landfills containing CNTs, it may be possible for CNTs to pass through the barriers.…”

A zeta potential value determines the aggregate’s size of penta-substituted [60]fullerene derivatives in aqueous suspension whereas positive charge is required for toxicity against bacterial cells

“…Other morphological characteristics (length, width, and height) of E. coli cells were weak changed only except for F2 compound, where the cell’s morphology changed more significantly. However, no evidences for appearance of grooves or lesions of the outer membrane or intracellular content efflux were observed thus suggesting that membrane disruption can hardly be considered as a leading mechanism of the antibacterial action of the fullerene derivatives [ 12 , 29 ].…”