title: Mitigation of Fe(0) nanoparticles toxicity to Trichosporon cutaneum by humic substances.
abstract: Zero-valent iron nanoparticles (nZVI) are a relatively new option for the treatment of contaminated soil and groundwater. However, because of their apparent toxicity, nZVI in high concentrations are known to interfere with many autochthonous microorganisms and, thus, impact their participation in the remediation process. The effect of two commercially available nZVI products, Nanofer 25 (non-stabilized) and Nanofer 25S (stabilized), was examined. Considerable toxicity to the soil yeast Trichosporon cutaneum was observed. Two chemically different humic substances (HSs) were studied as a possible protection agent that mitigates nZVI toxicity: oxidized oxyhumolite X6 and humic acid X3A. The effect of addition of HSs was studied in different phases of the experiment to establish the effect on cells and nZVI. SEM and TEM images revealed an ability of both types of nZVI and HSs to adsorb on surface of the cells. Changes in cell surface properties were also observed by zeta potential measurements. Our results indicate that HSs can act as an electrosteric barrier, which hinders mutual interaction between nZVI and treated cell. Thus, the application of HS seems to be a promising solution to mitigating the toxic action of nZVI.
authors.affiliation: University of Chemistry and Technology, Prague, Department of Biotechnology, Technická 5, 166 28 Prague, Czech Republic.
authors.forename: Karolína
authors.initials: K
authors.lastname: Pádrová
authors.affiliation: University of Chemistry and Technology, Prague, Department of Biotechnology, Technická 5, 166 28 Prague, Czech Republic. Electronic address: olga.matatkova@vscht.cz.
authors.forename: Olga
authors.initials: O
authors.lastname: Maťátková
authors.affiliation: University of Chemistry and Technology, Prague, Department of Biotechnology, Technická 5, 166 28 Prague, Czech Republic.
authors.forename: Michaela
authors.initials: M
authors.lastname: Šiková
authors.affiliation: University of Chemistry and Technology, Prague, Department of Biochemistry and Microbiology, Technická 5, 166 28 Prague, Czech Republic.
authors.forename: Tibor
authors.initials: T
authors.lastname: Füzik
authors.affiliation: University of Chemistry and Technology, Prague, Department of Biotechnology, Technická 5, 166 28 Prague, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Masák
authors.affiliation: University of Chemistry and Technology, Prague, Department of Biotechnology, Technická 5, 166 28 Prague, Czech Republic.
authors.forename: Alena
authors.initials: A
authors.lastname: Čejková
authors.affiliation: University of Chemistry and Technology, Prague, Department of Biotechnology, Technická 5, 166 28 Prague, Czech Republic.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Jirků
mesh_terms: D006812:Humic Substances / Q000032:analysis*; D007501:Iron / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000633:toxicity*; D055672:Static Electricity; D014250:Trichosporon / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D006812:Humic Substances; D007501:Iron