Evaluation of toxicity in aquatic organisms (Danio rerio) and soil microbes exposed to metallic nanoparticles (TiO2, Ag and Fe-NP-NP) using biochemical and genetic markers

Abstract

Due to high investment on developing and producing commercial goods using nanotechnology, it has become almost inevitable the contact of these materials with the human beings and the environment. The interaction with ecosystems and organisms is likely to occur because the commercial goods release this material to the environment, such as, the use of silver nanoparticles in the textil industry, or TiO2 in cosmetics. In the soil, nanoparticles can suffer alterations and interact with its components, increasing the toxicity. In relation to aquatic ecosystems there are several factors that influence the toxicity of the nanoparticles, like shape, size, dose and time of exposition. In this context, the proposal of this abstract is to evaluate the toxicity of antioxidant systems of metalic nanoparticles (silver, iron oxide and titaniun dioxide), due to the current great use of these materials in commercial goods. To perform this study, it will be investigated the effects of these naomaterials in organisms exposed to them, as well as, its effects in the soil microbiota. The tests in organisms will be performed through the evaluation of the cromossomic aberration in Allium cepa, comet assay, antioxidant systems (GSH, reduced glutathione, LPO, lipoperoxidation, carbonyl proteins, GST, glutathione S-transferase and CAT, catalase) and determination of the nuclear transition factor (Nrf2) in zebrafish fish (Danio rerio). To evaluate the effects of the nanoparticles in the soil microbiota, it will be used ARDRA molecular biology techniques (Analyses on the Restriction of Amplified Ribosomal DNA) and PCR in real time through the use of specific primers for the gene region 16SrRNA for the evaluation of the diversity and total quantification of the microorganisms and specific primers for genes of monoxigenases enzymes, nitrogenase reductases, nitrite reductase, nitrate reductase and nitro oxidase reductase in an attempt to quantify specific bacterias. This way, this study aims at obtaining information about the toxicity of nanoparticles to the organisms in order to generate knowledge about the safety of these materials in relation to the organisms in their environment, and with the possibility of contributing to the development of new systems that can cause less environmental impact. (AU)