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The neglected nano-specific toxicity of ZnO nanoparticles in the yeast Saccharomyces cerevisiae.

Zhang W, Bao S, Fang T - Sci Rep (2016)

Bottom Line: The toxic effects in the yeast were slightly attributable to dissolved zinc ions from the ZnO (nano or bulk) particles.Oxidative damage and mechanical damage contributed to the toxic effect of the ZnO particles.The mechanism of mechanical damage is proposed to be an inherent characteristic underlying the nano-specific toxicity in the mutants.

View Article: PubMed Central - PubMed

Affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.

ABSTRACT
Nanoparticles (NPs) with unique physicochemical properties induce nano-specific (excess) toxicity in organisms compared with their bulk counterparts. Evaluation and consideration of nano-specific toxicity are meaningful for the safe design and environmental risk assessment of NPs. However, ZnO NPs have been reported to lack excess toxicity for diverse organisms. In the present study, the nano-specific toxicity of ZnO NPs was evaluated in the yeast Saccharomyces cerevisiae. Nano-specific toxicity of ZnO NPs was not observed in the wild type yeast. However, the ZnO NPs induced very similar nano-specific toxicities in the three mutants with comparable log Te ((particle)) values (0.64 vs 0.65 vs 0.62), suggesting that the mutants were more sensitive and specific for the NPs' nano-specific toxicity. The toxic effects in the yeast were slightly attributable to dissolved zinc ions from the ZnO (nano or bulk) particles. Oxidative damage and mechanical damage contributed to the toxic effect of the ZnO particles. The mechanism of mechanical damage is proposed to be an inherent characteristic underlying the nano-specific toxicity in the mutants. The log Te ((particle)) was a useful parameter for evaluation of NPs nano-specific toxicity, whereas log Te ((ion)) efficiently determined the NPs toxicity associated with released ions.

No MeSH data available.


Related in: MedlinePlus

The morphology of yeast strain cells exposed to nano ZnO (10 mg/L).(A) normal cell, (B) cell cytoplasm leakage, (C) crushed cell wall, (D) partially crushed cell wall, (E) irregularly shaped cell, (F) deformed cell with sunken area.
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f3: The morphology of yeast strain cells exposed to nano ZnO (10 mg/L).(A) normal cell, (B) cell cytoplasm leakage, (C) crushed cell wall, (D) partially crushed cell wall, (E) irregularly shaped cell, (F) deformed cell with sunken area.

Mentions: The TEM images indicated that the yeast morphologies following ZnO NPs exposure were dramatically different compared with normal yeast cells (see Fig. 3). The cell walls of some of the yeast were broken or partially broken (Fig. 3C,D). The phenomenon was also observed in E. coli29. In the other yeast, although the cell walls were not crushed completely, the ZnO NPs-treated cell walls were deformed with some sunken areas (Fig. 3F) or deficiencies (Fig. 3E). Figure 3E indicated that the yeast cell walls were disrupted and that the morphology of the normal cell changed from globular to an irregular shape.


The neglected nano-specific toxicity of ZnO nanoparticles in the yeast Saccharomyces cerevisiae.

Zhang W, Bao S, Fang T - Sci Rep (2016)

The morphology of yeast strain cells exposed to nano ZnO (10 mg/L).(A) normal cell, (B) cell cytoplasm leakage, (C) crushed cell wall, (D) partially crushed cell wall, (E) irregularly shaped cell, (F) deformed cell with sunken area.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837412&req=5

f3: The morphology of yeast strain cells exposed to nano ZnO (10 mg/L).(A) normal cell, (B) cell cytoplasm leakage, (C) crushed cell wall, (D) partially crushed cell wall, (E) irregularly shaped cell, (F) deformed cell with sunken area.
Mentions: The TEM images indicated that the yeast morphologies following ZnO NPs exposure were dramatically different compared with normal yeast cells (see Fig. 3). The cell walls of some of the yeast were broken or partially broken (Fig. 3C,D). The phenomenon was also observed in E. coli29. In the other yeast, although the cell walls were not crushed completely, the ZnO NPs-treated cell walls were deformed with some sunken areas (Fig. 3F) or deficiencies (Fig. 3E). Figure 3E indicated that the yeast cell walls were disrupted and that the morphology of the normal cell changed from globular to an irregular shape.

Bottom Line: The toxic effects in the yeast were slightly attributable to dissolved zinc ions from the ZnO (nano or bulk) particles.Oxidative damage and mechanical damage contributed to the toxic effect of the ZnO particles.The mechanism of mechanical damage is proposed to be an inherent characteristic underlying the nano-specific toxicity in the mutants.

View Article: PubMed Central - PubMed

Affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.

ABSTRACT
Nanoparticles (NPs) with unique physicochemical properties induce nano-specific (excess) toxicity in organisms compared with their bulk counterparts. Evaluation and consideration of nano-specific toxicity are meaningful for the safe design and environmental risk assessment of NPs. However, ZnO NPs have been reported to lack excess toxicity for diverse organisms. In the present study, the nano-specific toxicity of ZnO NPs was evaluated in the yeast Saccharomyces cerevisiae. Nano-specific toxicity of ZnO NPs was not observed in the wild type yeast. However, the ZnO NPs induced very similar nano-specific toxicities in the three mutants with comparable log Te ((particle)) values (0.64 vs 0.65 vs 0.62), suggesting that the mutants were more sensitive and specific for the NPs' nano-specific toxicity. The toxic effects in the yeast were slightly attributable to dissolved zinc ions from the ZnO (nano or bulk) particles. Oxidative damage and mechanical damage contributed to the toxic effect of the ZnO particles. The mechanism of mechanical damage is proposed to be an inherent characteristic underlying the nano-specific toxicity in the mutants. The log Te ((particle)) was a useful parameter for evaluation of NPs nano-specific toxicity, whereas log Te ((ion)) efficiently determined the NPs toxicity associated with released ions.

No MeSH data available.


Related in: MedlinePlus