Nanopartículas de oro y sus efectos sobre microorganismos acuáticos, un estudio sobre "Daphnia Pulex"

Author(s):  
Paulina Abrica-González ◽  
◽  
José Abraham Balderas-López ◽  
Ernesto Zumelzu-Delgado ◽  
Jorge Nimptsch-Maass ◽  
...  
Keyword(s):  

En las últimas décadas, la nanotecnología ha emergido como un área de investigación que está encontrando aplicaciones en múltiples campos. El mercado actual incluye nanomateriales que proporcionan grandes ventajas sobre los materiales en su forma convencional, una de éstas, su mayor área de contacto, lo que los hace ideales como sustancias catalíticas, mejorando este tipo de procesos con la consecuente reducción de insumos. Dentro de los nanomateriales comúnmente utilizados, las nanopartículas de oro se han aplicado principalmente en biomedicina, salud y belleza, sector automotriz y electrónica. Sin embargo, el uso cada vez más generalizado de nanopartículas no va aparejado con estudios sobre el impacto ambiental que conlleva la disposición final de sus residuos, especialmente en medios acuáticos, destino habitual de muchas sustancias utilizadas en procesos industriales, los cuales han sido poco estudiados. La presente investigación aborda el efecto que tienen las nanopartículas de oro con recubrimiento de quitosano sobre Daphnia pulex, microorganismos generadores primarios en la cadena trófica. Como resultado fundamental de este trabajo se estableció una dosis letal media (EC50) de 0.5721 mg/L de Au en este tipo de microorganismos, este estudio confirma así la importancia de llevar a cabo más investigación sobre la toxicidad de nanopartículas funcionalizadas, especialmente de oro, en organismos acuáticos microscópicos que son la base de muchas cadenas tróficas en ríos y lagos.

1999 ◽  
Vol 39 (10-11) ◽  
pp. 173-176 ◽  
Author(s):  
Liesl Hill ◽  
Sebastian Jooste

With the increasing focus on environmental issues, the objective of this study is to evaluate the potential impact of contaminated sediments of the Blesbok Spruit near Witbank - which receives acid mine drainage (AMD) inter alia - on biota. Direct transfer of chemicals from sediments to organisms is considered to be a major route of exposure for many species, and therefore focusing attention on sediment contamination and highlighting the fact that sediments are an important resource. Acute toxicity tests were performed on Daphnia pulex using both extracted sediment interstitial water and surface water. Chemical analyses were also performed on the sediment, interstitial water and surface water samples. The toxicity results suggest that metal toxicity adds significantly to the toxicity of the stream water which is enhanced by the effect of pH. The pH of the stream and interstitial water was consistently below 4.5.


Author(s):  
Chongyuan Lin ◽  
Mengdi Liu ◽  
Xiaojing Zhu ◽  
Mengmeng Zhang ◽  
Shanliang Xu ◽  
...  

Limnology ◽  
2021 ◽  
Author(s):  
Yurie Otake ◽  
Hajime Ohtsuki ◽  
Jotaro Urabe ◽  
Kazuyoshi Yamada ◽  
Takehito Yoshida

Author(s):  
Eva Klumpen ◽  
Nadine Hoffschröer ◽  
Andrea Schwalb ◽  
Ulrike Gigengack ◽  
Marita Koch ◽  
...  
Keyword(s):  

Ecotoxicology ◽  
2021 ◽  
Author(s):  
Kurt A. Gust ◽  
Guilherme R. Lotufo ◽  
Natalie D. Barker ◽  
Qing Ji ◽  
Lauren K. May

AbstractThe US Department of Defense (DOD) is developing insensitive munitions (IMs) that are resistant to unintended detonation to protect warfighters. To enable material life-cycle analysis for the IM, 1-methyl-3-nitro-1-nitroguanidine (MeNQ), ecotoxicological impacts assessment was required. A previous investigation of MeNQ exposures in Daphnia pulex revealed concentration-responsive decreases in reproduction relative to controls (0 mg/L) across a 174, 346, 709, 1385, and 2286 mg/L exposure range. The present study used those exposures to conduct global transcriptomic expression analyses to establish hypothetical mode(s) of action underlying inhibited reproduction. The number of significantly affected transcripts and the magnitude of fold-change differences relative to controls tended to increase with increasing MeNQ concentration where hierarchical clustering analysis identified separation among the “low” (174 and 346 mg/L) and “high” (709, 1385, and 2286 mg/L) exposures. Vitellogenin is critical to Daphnia reproductive processes and MeNQ exposures significantly decreased transcriptional expression for vitellogenin-1 precursor at the lowest exposure level (174 mg/L) with benchmark dose (BMD) levels closely tracking concentrations that caused inhibited reproduction. Additionally, juvenile hormone-inducible protein, chorion peroxidase, and high choriolytic enzyme transcriptional expression were impacted by MeNQ exposure having potential implications for egg production / maturation and overall fecundity. In concert with these effects on specific genes involved in Daphnia reproductive physiology, MeNQ exposures caused significant enrichment of several canonical-pathways responsible for metabolism of cellular energy substrates where BMD levels for transcriptional expression were observed at ≤100 mg/L. These observations imply possible effects on whole-organism energy budgets that may also incur indirect costs on reproduction.


PLoS ONE ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. e0152436 ◽  
Author(s):  
Wenping Wang ◽  
Kun Zhang ◽  
Daogui Deng ◽  
Ya-Nan Zhang ◽  
Shuixiu Peng ◽  
...  

BMC Genomics ◽  
2009 ◽  
Vol 10 (1) ◽  
pp. 169 ◽  
Author(s):  
William S Baldwin ◽  
Peter B Marko ◽  
David R Nelson

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