Ecotoxicity of selected nanoparticles in relation to micro-organisms in the water ecosystem
Nina Doskocz , Monika Załęska-Radziwiłł , Katarzyna Anna Affek , Maria Lucyna Łebkowska
In the literature, there are few ecotoxicological data concerning the effects of nanoparticles on reducers, which are an important element of the food chain in aquatic ecosystems. The work aimed to evaluate the influence of two types of engineering nanoparticles: aluminum oxide (nano-Al2O3) and zirconium oxide (nano-ZrO2) on micro-organisms. In this work enzymatic assay (bioluminescence test) with Vibrio fischeri was performed as well as two growth tests: test with Pseudomonas putida and test microbial assay for toxic risk assessment with 10 species of bacteria and 1 species of fungi). In this study, the effect of the activity of nano-Al2O3 and nano-ZrO2 on micro-organisms as compared to their bulk counterparts. The obtained values of concentrations of EC50 and no observed effect concentrations showed a different sensitivity of the organisms to the examined compounds. According to the European Union criteria, nano-Al2O3 was very toxic to P. putida (EC50 = 0.5 mg/L), while nano- ZrO2 was harmful to Pichia anomala (EC50 = 89.80 mg/L) and P. putida (EC50 = 25.4 mg/L). Nanoparticles proved to be more toxic to tested micro-organisms than their bulk counterparts. This indicates that the nano-form of a given substance may pose a greater hazard for the environment than the same substance in the large form.