ABSTRACT
The antimicrobial activity of silver nanoparticles (AgNP) makes them useful in a wide range of products although their environmental impact is still uncertain. The main goal of this study was to evaluate short-term effects induced by AgNP on gills oxidative status and bacterial communities living at the skin mucus of zebrafish. Both the number of bacteria colony forming units and bacteria growth obtained from skin mucus were lower in all concentrations tested (25, 50 and 100 µg nAg/L). Besides, AgNP exposure caused a significant decrease in bacteria growth in zebrafish exposed to 100 µg nAg/L. AgNP accumulated in zebrafish gills at both highest concentrations tested, but this accumulation did not appear to result in oxidative stress. Overall the results indicated toxicological effects of AgNP on bacteria communities living at the zebrafish mucus surface. Although silver accumulation was verified in gills, no evidence of toxicity in terms of oxidative stress was found.
Subject(s)
Metal Nanoparticles/toxicity , Oxidative Stress/drug effects , Silver/toxicity , Water Pollutants, Chemical/toxicity , Animals , Bacteria/drug effects , Gills/metabolism , ZebrafishABSTRACT
This study analyzed the growth and biochemical responses of six bacterial colonies isolated from the mucus of the estuarine polychaeta Laeonereis acuta (Nereididae) after exposure to a water suspension of fullerene (nC60) and nanosilver (nAg) separately (0.01; 0.10; and 1.00 mg/L) and together (0.01; 0.10; and 1.00 mg/L of nanosilver and 1.00 mg/L of fullerene added to each nAg concentration). Exposures were performed in darkness during 24 h and then samples were taken from the worms and inoculated on agar during 24 h to analyze colonies growth. After this the material was analyzed biochemically. Colonies growth (tested by wet biomass weight) was inhibited at 0.01 and 0.10 mg/L of nAg and 0.01 and 0.10 mg/L nAg + constant 1.00 mg/L of nC60 (p < 0.05). Lipid peroxidation damage was significant from the control for the concentrations of 0.01 and 0.10 mg/L of nC60 and glutathione-S-transferase (GST) activity was significantly higher for the concentration of 1.00 mg/L mg/L nAg + constant 1.00 mg/L of nC60 (p < 0.05). Although nC60 did not induced growth inhibition, it triggered lipid peroxidation alone and increased GST activity together with nAg.60 Contrary to nC60, nanosilver inhibited bacterial growth, although the biochemical measurements indicate that this response is not due to reactive oxygen species generation.
Subject(s)
Bacteria/drug effects , Fullerenes/toxicity , Nanostructures/toxicity , Polychaeta/microbiology , Silver/toxicity , Animals , Bacteria/growth & development , Colony Count, Microbial , DNA Primers/genetics , Dose-Response Relationship, Drug , Glutathione Transferase/metabolism , Lipid Peroxidation/drug effects , Nanostructures/analysis , Silver/chemistry , Thiobarbituric Acid Reactive SubstancesABSTRACT
Fullerene (nC60) and nanosilver (nAg) are nanomaterials with bactericide properties. The increments in their use raise questions about their potential environmental impacts, including estuarine ones. The polychaete Laeonereis acuta (Nereididae) secretes mucus that is colonized by bacteria communities. We analyzed the antioxidant and oxidative damage responses of anterior, middle and posterior region of L. acuta and bacteria communities after nC60 or nAg exposure during 24 h. Molecular analysis showed a prevalence of Vibrio genera in the communities. Bacteria biomass was lowered in worms exposed to 1.0 mg/L of nAg. nC60 reduced total antioxidant capacity of bacteria from worms exposed to 0.1 mg/L. Worms anterior region presented lower antioxidant capacity after exposure to 1.0 mg nC60/L, and the same was observed in the posterior region of worms exposed to 1.0 mg nAg/L. Lipid peroxidation was reduced in the anterior region of worms exposed to nC60 and the opposite was observed in the posterior region.
Subject(s)
Anti-Bacterial Agents/toxicity , Fullerenes/toxicity , Metal Nanoparticles/toxicity , Polychaeta/drug effects , Silver/toxicity , Water Pollutants, Chemical/toxicity , Animals , Antioxidants/metabolism , Biomass , Lipid Peroxidation , Oxidative Stress/drug effects , Polychaeta/microbiology , Population Dynamics , Silver/chemistry , Silver/metabolismABSTRACT
Presenta una innovación radical basada en el estado de arte en nanotecnología y orientada a viabilizar, la aplicación de nanomateriales a problemas que requieren un uso masivo de este tipo de compuestos como la remediación ambiental
Subject(s)
Hydrocarbons , Environmental Restoration and Remediation , SoilABSTRACT
Presenta una innovación radical basada en el estado de arte en nanotecnología y orientada a viabilizar, la aplicación de nanomateriales a problemas que requieren un uso masivo de este tipo de compuestos como la remediación ambiental
